Weeds of Lawns and
Gardens
This Photo by Unknown author is licensed under CC BY-SA.

• Weeds are unwanted plants that
compete with the desired plants for
resources such as water, nutrients,
and sunlight. They can be a major
problem for lawns and gardens, as
they can reduce the overall health
and appearance of the landscape.
• It is important to understand the
types of weeds that are common in
your area, as well as their growth
habits and life cycles. This
knowledge can help you develop an
effective weed control strategy that
is both safe and environmentally
friendly.
This Photo by Unknown author is licensed under CC BY-SA.

• Prevention is the best approach to
weed control. This can include
practices such as proper watering and
fertilization, regular mowing, and the
use of mulch to prevent weed seeds
from germinating. When weeds do
appear, it is important to take action
quickly to prevent them from spreading
and becoming a larger problem.
• There are several methods of weed
control, including hand-pulling, hoeing,
and the use of herbicides. It is
important to choose the appropriate
method based on the type of weed and
the severity of the infestation.
This Photo by Unknown author is licensed under CC BY-NC.

• As a professional in the lawn
and garden care industry, it is our
responsibility to provide our
clients with the best possible
service and advice. By staying
informed and up-to-date on the
latest developments in weed
control, we can help our clients
achieve beautiful and healthy
landscapes.

• To conduct an effective weed management program, the
manager should be able to identify target weeds to genus and
preferably to species (for example: Poa annua. Poa is the genus
name and annua is the species name for annual bluegrass).
Accurate weed identification is essential to selecting the
appropriate control technique. Grasses are monocotyledonous
plants, which mean they have only one seed leaf (cotyledon)
present when a grass seedling emerges from the soil. Grasses have
joints (nodes) and hollow, rounded stems. The true leaves (as
opposed to seed or cotyledon leaves) have parallel veins and are
several times longer than they are wide. Bermudagrass, crabgrass,
goosegrass and annual bluegrass are typical grass weeds found in
ornamentals.

• Broadleaf weeds are
dicotyledonous, which means they
have two cotyledons at emergence
and have net-like veins in their
true leaves. Broadleaves often
have colorful flowers compared to
the inconspicuous flowers found
on grasses. Chick weed, henbit,
lespedeza, clover, dandelion and
dock are typical broadleaf weeds.

•Sedges have solid, triangular stems (in most
species) which bear leaves extending in three
directions (3-ranked). Sedges lack ligules and
auricles, and the leaf sheath is continuous around
the stem. Yellow and purple nutsedge, annual
sedge, green kyllinga, rice flat sedge and globe
sedge are examples.

Weed Life Cycles
The previously listed weed classifications may be further divided into
annuals, biennials and perennials. Annuals germinate from seed,
grow, mature and die in less than 12 months.
Annuals may be further classified as winter and summer annuals.
Winter annuals germinate in the fall, grow during cool periods, mature in
the spring and then die during the summer.
Summer annuals germinate in the spring, grow actively during the
summer and die in the fall. Crabgrass and goosegrass are examples of
summer annual grasses. Prostrate knotweed is an example of a summer
annual broadleaf, while henbit and chickweed are representative of winter
annual broadleaves.

• Biennials reproduce from seed and complete their life cycle
in two years. Biennials form rosettes and store foods in their
fleshy roots the first year and then flower the second year.
Many thistle species are biennials.

Perennial weeds live more than two years. Perennials may reproduce from
seed or from vegetative structures such as roots, rhizomes, stolons, tubers or
bulbs. The ability to reproduce vegetatively makes perennials more difficult to
control. Some perennials such as dandelion, dock and wild garlic are actively
growing during cool weather, while others like dallisgrass and nutsedge grow
rapidly during the summer months. Perennials are further subdivided as
simple perennials and creeping perennials. Simple perennials, such as dock
and dande lion, overwinter by means of a vegetative structure such as a
perennial root with a crown, but they reproduce almost entirely by seed.
Creeping perennials can both over winter and produce new independent
plants from vegetative reproductive structures.
Vegetative reproductive structures include creeping roots, stolons
(bermudagrass), rhizomes (johnsongrass), tubers (nutsedge) and bulbs (wild
garlic). Most perennials can also reproduce from seed.

• Herbicides
• A selective herbicide controls or
suppresses some plant species
without seriously affecting the growth
of another plant species.
• Selectivity may be due to differential
absorption, translocation,
morphological and/or physiological
differences between ornamentals and
weeds.
• Most ornamental herbicides are
selective. Fusilade II is an example of
a selective herbicide that controls
many grass weeds without causing
significant injury to broadleaf plants.
This Photo by Unknown author is licensed under CC BY.

• Nonselective herbicides control or
suppress plants regardless of
species. Glyphosate (Roundup Pro),
glufosinate (Finale) and diquat
(Reward) are examples of non-
selective herbicides. These products
are often used for trimming along
sidewalks and fences and as preplant
treatments when renovating or
establishing ornamentals. It is
important to note that the selectivity
of some herbicides is based on rate.
Increasing the rate of a selective
herbicide such as Princep (simazine)
will move it into the nonselective
category.
This Photo by Unknown author is licensed under CC BY.

• Mode of action refers to the sequence of events, which
includes herbicide absorption, translocation to the site(s)
of action, inhibition of a specific biochemical reaction,
the degradation or breakdown of the herbicide in the
plant and the effect of the herbicide on plant growth and
structure.

Herbicide Movement in Plants
• Systemic (sometimes referred to as translocated) herbicides are
extensively translocated in the vascular system of the plant. The
vascular system consists of the xylem and phloem. The xylem
transports water and various nutrients in solution upward from the
roots where they entered the plant, through the stems and into leaves,
flowers and fruits.
The phloem conducts food materials from their principal sites of
synthesis in leaves to other locations, such as fruits and developing
roots and shoots, for storage and use. Systemic herbicides are slower
acting than contact herbicides because they require from several days
to a few weeks to move throughout the vascular system of a treated
plant. Systemic herbicides may be selective or nonselective.

Herbicide
Movement in Plants
• Glyphosate (Roundup Pro) is
an example of a nonselective
systemic herbicide, while
Vantage (sethoxydim) is an
example of a selective systemic
herbicide. Most of the systemic
herbicides move in the xylem
and phloem with the exception
of the triazines (atrazine,
simazine, Sencor) which are
xylem mobile only.
This Photo by Unknown author is licensed under CC BY-ND.

• Contact herbicides affect only the green plant tissue that comes in
contact with the herbicide spray. Thus, thorough coverage of the weed
foliage is needed to achieve optimum control. These herbicides are
either not trans located or only move to a limited extent within the
vascular system of plants. For this reason, underground vegetative
reproductive structures such as roots, rhizomes and tubers are not
affected. Multiple applications of contact herbicides are needed for
long-term control because plants regrow from these unaffected plant
parts.
Contact herbicides are fast acting. Symptoms are often visible within a
few hours of application. Basagran T/O (bentazon) is a selective contact
herbicide. Reward (diquat) is a nonselective contact herbicide.

• Herbicide Families
• Herbicides with similar chemistry are
grouped into families. In general,
herbicides in the same family exhibit
similar absorption, translocation and mode
of action. It is convenient to combine
herbicide families that have
similar sites of action into groups. For
ornamental weed managers, the
importance of knowing which herbicides
have similar sites of action
lies in developing weed control strategies
that minimize the potential for developing
herbicide-resistant weed populations.

Pre-emergence herbicides are the foundation of an ornamental weed
management program. Pre-emergence herbicides are applied to the site
before weed seed germination. After being activated by rainfall or irrigation,
these herbicides form an herbicide barrier at or just below the soil surface.
When the roots or shoots of germinating seeds come in contact with the
herbicide barrier, their growth is inhibited. Most preemergence herbicides
are cell division inhibitors affecting the emerging root and shoot, which are
sites of rapid cell division. Weeds that have already emerged (visible) are
not consistently controlled because their growing point has escaped contact
with the herbicide. The primary target of pre-emergence herbicides is
annual grass, but some small-seeded annual broadleaves will be controlled.

A variety of factors affect the performance of
preemergence herbicides. These include timing of
application in relation to weed seed germination,
soil type, environmental conditions (primarily
temperature and rainfall), target weed species and
biotype and cultural practices that follow
application. Soil organic matter and clay content
have the greatest influence on the activity of pre-
emergence herbicides.

Ideally, pre-emergence herbicides should be applied just before weed seed
germination begins. Applying too early may result in reduced control or no
control due to leaching and/or normal herbicide degradation.
Pre-emergence herbicides must be in place and activated before the onset of
weed seed germination. Activation of pre-emergence herbicides requires 0.25
to 0.5 inch of rainfall or overhead irrigation. For optimum performance,
rainfall or irrigation should occur within 24 hours of application. Water moves
the herbicides into the upper layer of the soil. Failure to incorporate
herbicides will result in loss through processes such as breakdown by sunlight
and escape into the atmosphere as a gas.

• The critical period between application
and activation by rainfall or irrigation
varies with herbicide, rate and
environmental conditions. However, it is
safe to assume that sooner is better and, if
irrigation is available, water-in pre-
emergence herbicides immediately after
application. In warm weather, herbicides
begin to degrade soon after application,
eventually reaching a level at which weed
emergence and growth can occur. Pre-
emergence herbicides will degrade to the
point of ineffectiveness from one to four
months after application. For this reason,
repeat or sequential applications are
needed for full-season control.

• A typical cycle of pre-emergence herbicide applications
would include an initial application in late winter to early
spring to control summer annuals followed by second
application in late summer to early fall to control winter
annuals. In some parts of the country, such as the humid
South, an application in late May or early June may be needed
because the spring application will have dissipated by that
time. (The application timing in your state may vary.)

• Post emergence herbicides are intended for use on weeds that
have emerged and are visible. Post emergence herbicides are
applied directly to emerged weeds. In contrast to pre-emergence
herbicides, most post-emergence herbicides have little or no soil
activity. It is possible to conduct a total post emergence weed
control program in ornamentals provided multiple applications are
used throughout the year. Disadvantages of total post emergence
weed control include the need for frequent applications and the
possibility of temporary ornamental injury.

• Most weed control professionals use a combination of pre-emergence and
post emergence herbicides. Pre-emergence herbicides form the basis of
most programs, with post emergence herbicides used to control weeds that
escape the pre-emergence treatments.
• Established perennial weeds, both grasses and broadleaves, must be
controlled with post emergence herbicides.
• General guidelines for best results with post emergence applications are
small weeds, adequate soil moisture and air temperatures between 60 and
90ºF. Weeds that are small (two to four-leaf stages) and actively growing are
much easier to control with post emergence herbicides. Control is improved
at this stage because young weeds readily absorb and translocate herbicides.

Weeds that are stressed due to dry weather, heat or other environmental
factors are more difficult to control with post emergence herbicides.
Applying post emergence herbicides at temperatures above 90ºF increases
the risk of ornamental injury. The resistance of post emergence herbicides
to wash-off by rainfall or irrigation varies among products. Typically, a rain-
free period of 6 to 24 hours is sufficient to avoid a reduction in
effectiveness. Even if rain falls soon after application, some degree of
control will be achieved. Rather than a single rate, a range of post-
emergence herbicide rates for a product usually is given. Repeat
applications at moderate rates are generally more effective than a single
application of the higher rate. The follow up application is timed to be 7 to
14 days after the first, or when regrowth appears.

Directed spot spraying with a hand-held, pump-up sprayer or lever-operated
backpack sprayer is one of the most commonly used methods of applying
herbicides in and around landscape plantings. Lack of herbicide selectivity and
the obstructions created by landscape plants often dictate the use of this
approach. Spot spraying solutions are typically prepared by adding a certain
amount of liquid herbicide per gallon of spray mix. These are usually given on a
percent of total volume basis. For example, to make a 2% mixture of Roundup
and water, add 2.66 ounces of Roundup per gallon of water. This method is best
for herbicides with little or no soil activity. Soil active herbicides should be
carefully applied on a per unit area basis (per 1,000 square feet or per acre).

• When spraying, do not over apply. The coverage should be similar to
that resulting from a light rain. Just wet the foliage of the target weed and
move on. Do not spray until runoff.
• Remember that herbicides can injure nontarget or desirable plants.
When using any herbicide, research the characteristics of the
product and manage the application carefully.
Take steps to ensure that herbicides are directed to the target. Use them
at the proper rate, at the right time and on a site that the
label permits. Control each application so there is no off-target
movement. Herbicide movement may result from drift of spray droplets,
volatilization (movement as a gas), contaminated surface runoff water or
by tracking with feet or equipment.
This Photo by Unknown author is licensed under CC BY-SA.

• Environmental Factors Affecting
Pesticide Effectiveness
• Many factors determine the effectiveness
of a pesticide program. Using the right
pesticide and applying it correctly are the
most important factors that determine the
final outcome.
• However, there are some environmental
factors that can have a negative or positive
effect on pesticides. Environmental factors
that affect pesticides can be divided into
three (3) groups: climatic, plant and soil
factors.

• Climatic Factors
• Temperature affects the amount of
time required for a pesticide to do its
job. For example, when air
temperatures are between 65ºF to
85ºF, a plant is rapidly growing and
herbicides will be more effective.
Long periods of cold or hot
temperatures will slow down
herbicide activity.
• High humidity allows foliar-applied
pesticides to enter a plant quicker
than at low humidity. During a period
of high humidity and moderate
temperature is the optimum time to
spray a pesticide that must be taken
up by plant foliage.

• Precipitation soon after a pesticide
application may help or hurt the final
results.
A moderate (1 inch or less) rain just after
a soil-applied pre-emergence herbicide
or soil insecticide will move the product
down into the soil where it is needed. A
rain shortly after an application of a
foliar-applied herbicide or systemic
fungicide will drastically reduce the level
of control. Any pesticide that needs to be
taken up through the turf foliage should
not be applied if there is a good chance
of rain within a few hours. The decision
not to spray because of the possibility of
rain must be made by the applicator.
This Photo by Unknown author is licensed under CC BY-NC-ND.

• Wind is definitely the most
important climatic factor.
Excessive wind does not have a
direct effect on pesticide
effectiveness; however, indirectly it
is a major problem. Excessive wind
(greater than 10 mph) distorts
spray patterns and hinders the
application of the pesticide. Using
a drift control additive will help,
but knowing when not to spray
because of excessive winds is more
important. Applying pesticides in
the early morning or late evening
hours may help avoid the more
windy parts of the day.

Weed IPM for Ornamentals
Weed prevention is avoiding the introduction of weeds into an un-infested
area. One of the keys to making integrated pest management effective in
controlling ornamental weeds is not allowing weeds to become established.
Some common sense steps to weed prevention include:​
1. Using weed-free mulch.​
2. Using weed-free plant materials.
Container nursery stock and balled and burlap material may contain weeds.
While it may not be practical to return the plants, it will be possible to get a
jump on controlling these weeds.​
3. Keeping border areas weed-free and preventing weeds from
producing seeds.​
4. Washing equipment between uses.​
This Photo by Unknown author is licensed under CC BY-SA.

ANOTHER OPTION TO CONSIDER
• Advantages of Landscape Fabrics
• PROS
1. Fabrics reduce the need for, or replace the use of, chemicals
for weed control.
2. These products allow for water and gas exchange.
3. The rougher surface tends to hold mulch better than black plastic.
4. They provide long-term weed control if kept covered by mulch.
5. They improve weed control over mulch alone.

• Disadvantages of Landscape Fabrics
• CONS
1. They are more expensive than black plastic.
2. Installation is more difficult.
3. These materials will not control all weeds, especially perennial ones.
4. They may stimulate surface rooting of trees and shrubs.
5. Weed roots and shoots may grow through and become intertwined
in the fabric.
6. The roots of ornamentals may grow through and into the fabric.
7. Seems to create a favorable environment for rodents.

Weed IPM for Ornamentals
Weed prevention is avoiding the introduction of weeds into an uninfested area.
One of the keys to making integrated pest management effective in
controlling ornamentals weeds is not allowing weeds to become established.
Some common sense steps to weed prevention include:
1. Using weed-free mulch.
2. Using weed-free plant materials. Container nursery stock and balled
and burlap material may contain weeds.
While it may not be practical to return the plants, it will be possible
to get a jump on controlling these weeds.
3. Keeping border areas weed-free and preventing weeds from producing seeds.
4. Washing equipment between uses.

Landscape weed control is not herbicides alone. Approach weed control
as an integrated process that combines good cultural practices that will
produce dense, vigorous landscape plants with intelligent selection and
use of herbicides. To conduct an effective weed control program:
1. Provide proper cultural practices.
2. Have the ability to identify specific weeds.
3. Be familiar with the growth and reproductive characteristics of weeds.
Scout for weeds and pay attention to perennial species because they
have the greatest potential for creating future problems. The best time to
identify perennials is during late summer or early fall. Note the
location of various weed infestations. This information will allow you to
be ready with the correct plan of attack come treatment time.
4. Have knowledge of the control measures available and have the ability
to select and use them properly.

• Too often weed control measures
are a reaction to an immediate
problem rather than part of a well-
planned and coordinated program.
Weed control professionals should
spend at least as much time learning
the conditions that lead to weed
infestation as they do studying
control options after weeds have
become established.

• Pesticide Laws and Regulations
• “THE LABEL IS THE LAW”
• There are many federal and state laws
that regulate the use of pesticides.
These laws must be followed to the
best of your ability to insure the proper
results and protect people and the
environment from unnecessary dangers
and contamination. The best way to
meet most of these regulations is to
follow the directions on the pesticide
label. The label in itself is a “law,” and
all directions on the label are to be
followed. To do differently is to be in
violation of the label and the law.

• Regulatory Matters
• Re-entry Into Treated Areas
• Re-entry requirements have been established for
ornamental pesticides applications, as has been done
for many agricultural pesticides.
• Ornamental pesticide labels do address re-entry,
usually by stating, “...Keep children and pets off
treated areas until the sprays have dried.” Some
labels may provide a safe time for re-entry, such as 12
or 24 hours after treatment. Such label statements are
to be followed. They also must be considered when
selecting a pesticide. Such requirements for pesticides
to be used in parks and other high traffic areas can
cause extreme management problems for the
applicator.

• Endangered Species Act
• The Endangered Species Act (ESA) affects all federal programs and
agencies. Since the EPA registers pesticides, pesticides are covered under the
ESA. The act applies to all outdoor applications of pesticides.
• Basically, no person is to take any action that may harm or kill a federally
endangered or threatened species. This includes affecting the species
habitat or food source. Ornamental pesticide applicators are responsible for
determining whether or not their actions will harm an endangered species
in the area to be treated.
This Photo by Unknown author is licensed under CC BY-SA-NC.

• Pesticides can contaminate water throughout the
hydrologic cycle. Water contamination is directly related
to the degree of pollution in our environment. Rainwater
flushes airborne pollution from the skies. Pollution is
then washed over the land before running into rivers and
lakes and seeping into underground aquifers. Since
irrigation and drinking water come from surface and
ground water, any chemical used may pollute
our water supplies. While some substances that
endanger water quality come from agriculture, most
result from urban and industrial activity.
Some also come from pesticide use on ornamentals.
Whether in agricultural operations or in urban
environments, the improper application, handling or
disposal of pesticides can lead to water pollution.

• When selecting pesticides for use in ornamental settings, choose pesticides
that will control the pest and have the least ability to runoff or leach into the
soil. To achieve this balance, the applicator must be knowledgeable of a
pesticide’s efficacy and water solubility. Unfortunately, it is often difficult to
determine if a pesticide has the potential to leach or run off into water
sources. Water solubility information is available on the pesticide’s label and
the Material Safety Data Sheet (MSDS). However, many MSDS’s do not
provide water solubility or Koc information. For specific product information,
check reference sources and the company’s technical sheets. Areas that are
designed to drain require special consideration when selecting the
appropriate pesticide. Determine if the planting has drain tiles or other
drainage systems installed and know where these drainage systems empty. It
is not good to move contaminated water from a treated area into any water
system.

• Be prepared for accidents. Hoses sometimes break, drain plugs come out
and sprayers can accidentally be overturned. Have the appropriate spill
containment equipment in your vehicle.
• Ways Pesticides Can Contaminate Water
• Over application or misuse of pesticides can allow these materials to enter
the surface and/or ground water. For some of the newer pesticides, drift
from soil particles treated with the pesticide is a potential source of water
contamination. Newer pesticides are often active at very low concentrations
and, when bound to soil particles, the pesticide may be picked up by the
wind and moved over surface water. When deposited in water, the soil
particle with the pesticide attached can then move into the surface water.
This is generally not a major problem unless large amounts of contaminated
soil particles are moved and deposited in the same area or unless the
pesticide is active on other target species.

• Improperly cleaning pesticide containers and sprayers often leads to
pesticide runoff or contamination of the soil at the mixing/loading site.
Pesticide sprayers should be loaded and cleaned on an impervious
pad. This eliminates
concern about spills causing runoff or leaching problems, avoiding
potential contamination of wells from constant small spillages at the
same site.
• When filling any sprayer, either an anti-back-siphoning device or an
air gap should be used. This prevents the back siphoning of the
pesticide mix into the water line if water pressure is lost. If using anti-
back-siphoning devices, periodically inspect the device to ensure it is
functioning correctly. Mechanical back-siphoning devices have been
known to stick in the open position.

• Pesticide containers should be pressure or triple rinsed
immediately after emptying to rinse all the excess
pesticide from the container. The rinsate is to be rinsed
directly into the sprayer so the rinsate can be sprayed
on the labeled site. This provides a clean container that
can be recycled.

• Wildlife Safety
• The use of pesticides on turfgrass must also take into consideration possible
impact on wildlife. Many pesticides are toxic to fish and/or wildlife. Therefore, do
not spray pesticides in or on water or under situations that can lead to fish
and/or wildlife kills. Also, be careful that pesticides are not applied just before a
thunder storm or irrigation schedule. You do not want to wash the pesticide into
the water system.

• Weeds are unwanted
plants that can grow in
lawns and compete with
the grass and desirable
for nutrients, sunlight,
and water. Identifying
and controlling weeds is
an important part of
lawn care.

• The importance of weed
identification skills is obvious. It is
impossible to look for control
information until the weed has been
identified.
The ability to identify weeds is
important from more than a control
standpoint.
• Often, the first question a client is
going to ask is, “what is that weed?”
So, weed identification is also useful in
establishing your credibility as a
professional.

• Plantain: A perennial weed that
belongs to the Plantaginaceae family.
Plantain has broad, ribbed leaves and
tall, slender flower spikes. Plantain can
thrive in compacted or poorly drained
soil, and can be difficult to control once
it becomes established. It can grow up
to 12 inches tall and has a deep taproot.
Broadleaf plantain is a perennial weed
with large, oval-shaped leaves and small,
inconspicuous flowers. It is a common
weed in lawns and gardens, thriving in
compacted soil and areas with poor
drainage.

• It typically grows in
compacted soil and
areas with poor
drainage, such as lawns,
gardens, and fields.
Broadleaf plantain can
grow up to 12 inches in
height and has a deep
taproot system that can
extend several feet into
the ground. Its leaves are
large, oval-shaped, and
have prominent veins.
The flowers of the plant
are small, inconspicuous,
and usually grow on a
long stem.

• The plant produces a dense rosette of leaves
close to the ground, making it difficult to
remove by hand. The seeds of Broadleaf
Plantain can remain viable for several years,
allowing it to spread quickly and easily.

• Control measures for Broadleaf Plantain
include:
• Hand-pulling: Small infestations of Broadleaf
Plantain can be removed by hand-pulling or
using a hoe to dig out the roots.
• Lawn care: Maintaining a healthy, well-
fertilized lawn can help to prevent Broadleaf
Plantain from taking hold in the first place.
Proper mowing, watering, and fertilization can
help to keep the grass thick and healthy,
reducing opportunities for weeds to take hold.

• Herbicides: Chemical
herbicides can be
effective in controlling
Broadleaf Plantain, but
should be used with
caution as they can harm
desirable plants and can
have negative impacts
on the environment.
Selective herbicides that
target broadleaf plants,
such as 2,4-D or
dicamba, are typically
effective against
Broadleaf Plantain.

• Soil aeration:
Aerating the soil can
help to break up
compacted soil and
improve drainage,
reducing the
conditions that allow
Broadleaf Plantain to
thrive.
This Photo by Unknown author is licensed under CC BY.

• Mulching: Covering
the affected area
with a thick layer of
mulch can prevent
sunlight from
reaching the weed
and eventually kill it.

• Control: Broadleaf plantain can be removed
manually by digging out the entire root
system. It is important to maintain a healthy
lawn through proper fertilization, mowing,
and watering. Herbicides can also be used to
kill plantain, but may require multiple
applications.
This Photo by Unknown author is licensed under CC BY-NC-ND.

• Chickweed is a
member of the
Caryophyllaceae family
and is a low-growing
weed known for its
delicate appearance
with small white, star-
shaped flowers and
small, oval-shaped
leaves with a pointed
tip and a smooth.

• Chickweed can thrive in
moist, shady areas of the
lawn, and can quickly
spread to form dense
patches. It can grow up to
8 inches tall and forms
dense mats. Common
chickweed is a winter
annual weed that grows
low to the ground. It
thrives in cool, moist
conditions and can
quickly spread
throughout a lawn or
garden.

• Pre-emergent
herbicides: Applying pre-
emergent herbicides in
the fall can prevent
Common Chickweed
seeds from germinating
in the spring, reducing
the number of plants
that need to be
controlled.

• Control: Common
chickweed can be controlled
with post-emergent
herbicides or small
infestations of chickweed can
be removed by hand-pulling
or using a hoe to dig out the
roots. Herbicides: Chemical
herbicides can be effective in
controlling Common
Chickweed, but should be
used with caution as they can
harm desirable plants and
can have negative impacts on
the environment.

Crabgrass is an annual weed that grows low to the ground and
spreads out in a star-shaped pattern. It has wide, flat blades and
can grow up to 6 inches tall. It has light green, pointed leaves
that form a dense mat-like clump, and it spreads by seeds and
tillers that grow from the base of the plant. Crabgrass produces
a long, slender seedhead that can reach up to a foot tall and
easily reseeds itself in the lawn.

•Crabgrass thrives
in bare or thin
areas of the lawn,
and can quickly
spread to take over
large patches of
grass.

• Preventing the growth of
crabgrass requires maintaining
a healthy lawn through proper
watering, fertilization, and
mowing practices. A thick,
healthy lawn will help to
prevent the establishment of
crabgrass by shading the soil
and outcompeting the weed for
resources.

• In cases where
crabgrass has already
established,
preemergent herbicides
can be applied in the
spring to prevent seed
germination. Post
emergent herbicides can
also be used to
control crabgrass, but
they should be applied
when the weed is still
young and actively
growing.
This Photo by Unknown author is licensed under CC BY.
Regular mowing and
fertilization to promote a
healthy, dense lawn can help
prevent crabgrass from
becoming established.

• Dandelion (Taraxacum
officinale)are perennial
weeds that have bright
yellow flowers and
deeply notched leaves
that form a rosette.

• Dandelion: A perennial
weed with a deep
taproot, yellow flowers,
and a rosette of deeply
lobed leaves. Dandelions
can spread quickly and
their deep taproots
make them difficult to
pull up by hand.

• Dandelions produce seeds that are housed in a fluffy, white structure
called a pappus. The pappus is actually made up of many individual
hairs, each attached to a single seed. When the dandelion flower head
is fully mature, the pappus expands and the hairs become detached
from the seeds. This allows the seeds to be easily carried by the wind,
sometimes for miles away from the parent plant.
• The seeds of dandelions are highly adaptive and can germinate in a
wide variety of conditions. They can grow in both moist and dry soils
and are able to tolerate a range of soil pH levels. The seeds can also
remain viable in the soil for many years, waiting for the right conditions
to germinate.

• Control: Dandelions can
be removed manually by
digging out the entire root
system. They can also be
controlled with post-
emergent herbicides.

• Clover: A perennial
weed with leaves made
up of three leaflets and
small white or pink
flowers. Clover can fix
nitrogen in the soil,
which can be beneficial
for grass, but can also
create unsightly patches
in the lawn.

• To control clover, it is
important to maintain a
healthy lawn through
proper fertilization,
mowing, and watering.
Herbicides can also be
used to kill clover, but
should be applied
carefully to avoid
damaging surrounding
grass.

• White clover roots are relatively shallow, with the main taproot typically
only growing to a depth of about 6-8 inches (15-20 cm). The roots are
fibrous and form a dense mat just below the soil surface. This mat of roots
helps to improve soil structure and fertility by breaking up compacted soil
and adding nitrogen to the soil through a process called nitrogen fixation.

• White clover (Trifolium repens) produces
small, round seeds that are typically 1-2 mm
in diameter. The seeds are light brown in
color and have a hard, smooth outer coating.
• White clover seeds are commonly used in
agriculture as a cover crop, forage crop, or as
a component of grass seed mixes. When used
as a cover crop, white clover can help to
improve soil health by fixing nitrogen,
reducing erosion, and suppressing weed
growth. As a forage crop, white clover
provides a high-quality source of protein and
energy for grazing animals like cows, sheep,
and goats.

• Creeping Charlie
(Glechoma
hederacea)Creeping
Charlie is a perennial
weed that has scalloped
leaves and small blue-
violet flowers. It spreads
rapidly by creeping
stems that root at the
nodes.

• Creeping Charlie, also
known as ground ivy, a
perennial weed that grows
low to the ground and
spreads by producing
creeping stems or runners.
It has round or kidney-
shaped leaves with
scalloped edges and small,
funnel-shaped blue or
purple flowers.

• Creeping Charlie can
quickly take over a lawn
or garden bed,
outcompeting desirable
plants and reducing
overall biodiversity. It is
particularly difficult to
control because of its
persistent root system,
which can regenerate
from small pieces of
the stem left in the soil.

• Control measures for Creeping Charlie include:
• Hand-pulling: Small infestations of Creeping Charlie can be removed
by hand-pulling or using a hoe to dig out the roots.
• Mulching: Covering the affected area with a thick layer of mulch
can prevent sunlight from reaching the weed and eventually kill it.
• Herbicides: Chemical herbicides can be effective in controlling
Creeping Charlie, but should be used with caution as they can harm
desirable plants and can have negative impacts on the environment.
This Photo by Unknown author is licensed under CC BY-SA-NC.

• Spotted spurge is a
common weed in lawns,
gardens, and other areas
of disturbed soil. It is
particularly well adapted
to dry, sunny areas and
can tolerate a range of
soil types. It can be
difficult to control once
established, as it has a
deep taproot and can
regenerate from pieces
of stem or root left in
the soil.

• Spotted spurge is low-growing weed
that has small, oval-shaped leaves
that are light green with a red or
purple spot in the center, hence its
name. The leaves are arranged
opposite each other along reddish
stems that grow close to the ground,
and the plant produces small,
inconspicuous flowers in the summer.

• Spotted spurge, also known as prostrate
spurge, is a summer annual weed that spreads
by seeds and stems that root at the nodes.

• Preventing the growth of spotted spurge requires
maintaining healthy turf and avoiding soil disturbance. Hand
weeding and targeted spot treatments with herbicides, such
as those containing 2,4-D, dicamba, or glyphosate, can be
effective in controlling spotted spurge. However, repeated
applications may be necessary, as the weed can regenerate
from small pieces of stem or root left in the soil.
• It is important to follow label instructions carefully when
using herbicides to avoid damage to desirable plants.

• Yellow nutsedge, also known as chufa or
earth almond, is a perennial plant that
belongs to the Cyperaceae family. It is
native to North America, but can now be
found in many parts of the world, including
Europe, Africa, Asia, and Australia. The plant
is characterized by its triangular stem and
yellowish-brown flowers that appear in
clusters at the top of the stem.

• The plant can grow up
to 3 feet tall and has a
thick, fibrous root system
that can extend up to 3
feet deep into the soil.

• The leaves of the yellow
nutsedge plant are long and
narrow, measuring up to 1/2 inch
wide and 2 feet long. They are
arranged in a basal rosette and
have a smooth texture with a
bright green color. The plant
produces flower spikes that are
composed of several small flowers
that are arranged in clusters called
umbels. The flowers are yellowish-
brown in color and bloom in the
summer months.

• Yellow nutsedge is often
considered a weed
because it can quickly
spread and grow in a
variety of soil conditions. It
prefers wet or moist soils
but can also grow in dry
soils. It is often found in
agricultural fields, gardens,
lawns, and other disturbed
areas. The plant is capable
of reproducing both
sexually and asexually,
making it highly adaptable
and resilient.
This Photo by Unknown author is licensed under CC BY-NC.

• Controlling yellow nutsedge can be challenging because of its
extensive root system and ability to reproduce through tubers.
However, there are several methods that can be effective in managing
its growth:
Improving soil drainage and reducing soil moisture can make the
growing conditions less favorable for yellow nutsedge. Also, proper
lawn care practices such as regular mowing, adequate fertilization, and
irrigation management can help in controlling the plant.

This Photo by Unknown author is licensed under CC BY-SA-NC.
This Photo by Unknown author is licensed under CC BY.
• Hand pulling: Small patches of yellow nutsedge can be hand
pulled, ensuring that the entire plant and its underground parts
are removed. This method is best suited for small
infestations. Herbicides: Several herbicides are available for yellow
nutsedge control, including glyphosate, sulfentrazone, and
halosulfuron. Always read and follow the label instructions before
using any herbicides.
• Mulching: Mulching with organic materials such as straw, wood
chips, or leaves can help suppress the growth of yellow nutsedge.
• Solarization: This method involves covering the soil with clear
plastic and exposing it to the sun for several weeks. The heat
generated by the sun will kill the underground parts of the plant,
including the tubers.

• Cirsium arvense, commonly
known as the Canada thistle
or creeping thistle, is a
perennial weed native to
Eurasia but now found in
many parts of the world,
including North America,
South America, and Australia.
It is considered an invasive
species in many areas due to
its aggressive growth and
ability to spread quickly..

• Canada thistle typically grows
to a height of 30 to 150 cm (12
to 59 in) and has a deep and
extensive root system. The stem
of the plant is slender and
ridged, with spines along the
edges. The leaves are alternately
arranged, deeply lobed, and
spiny with a waxy coating, giving
them a grayish-green
appearance. The flowers are
purple, pink, or white and are
arranged in clusters at the ends
of the stems. They bloom from
June to August.

• Canada thistle can be confused with other
thistle species, including the bull thistle
(Cirsium vulgare) and the field thistle
(Cirsium discolor). Bull thistle has larger
flower heads and lacks the waxy coating on
its leaves, while field thistle has more
deeply divided leaves and a more branched
stem.

• Canada thistle grows
in a wide range of
habitats, including
fields, meadows,
pastures, roadsides,
waste areas, and
disturbed sites. It
prefers fertile, well-
drained soils, but can
also tolerate poor,
compacted, or
disturbed soils.

• Canada thistle
reproduces primarily by
seeds, which are
produced in large
quantities and dispersed
by wind and water. The
seeds can remain viable
in the soil for up to 20
years. The plant can also
spread vegetatively
through its extensive
root system, which can
send up new shoots
from lateral roots or
from buds on the
taproot.

• Controlling Canada thistle can be challenging due to
its deep and extensive root system and ability to
regrow from small root fragments. Methods for control
include digging up the roots, mowing or cutting the
stems repeatedly, applying herbicides, or using
biological control agents such as insects that feed on
the plant.

thistle (Genus Cirsium)
Thistles are typically herbaceous plants with spiny
leaves and purple, pink, or white flowers that
bloom in the summer.
The flowers are often arranged in spherical
or cylindrical clusters and are surrounded
by prickly bracts.

• Spiny: Thistle leaves are covered in sharp
spines that can be painful to touch. The
spines are typically located along the edges
of the leaves and on the stems of the plant.
Lobed: Thistle leaves are typically deeply
lobed, with the lobes extending almost to
the midrib of the leaf. The number and
shape of the lobes can vary depending on
the species. Rosette: Thistle leaves are
arranged in a rosette at the base of the
plant. This helps the plant to conserve
water and nutrients by reducing surface
area exposed to the sun and wind. Fuzzy:
Some species of thistle have leaves that are
covered in fine hairs or fuzz, which can help
to protect the plant from herbivores and
reduce water loss.

Habitat: Thistles can be found in a
wide range of habitats, including
grasslands, meadows, forests,
and wetlands.
Some species are adapted to dry
or rocky soils, while others
prefer moist or marshy areas.

Invasiveness: Some species of thistle are ​considered invasive and
can spread rapidly in certain environments, ​outcompeting native
plants and reducing biodiversity. ​These species are often difficult to
control and can cause problems ​for agriculture and home owners.

Thistles in the genus Cirsium
have deep and extensive
taproots ​that can reach
several feet in length and are
typically tough ​and fibrous.
The taproot is the primary
root of the​ plant, and it is
used to absorb water and
nutrients from the soil.

Competition with other plants: Thistles can outcompete other plants in yards
and gardens, reducing biodiversity and making it difficult for other plants to
grow and thrive.
Invasiveness: Some species of thistle are considered invasive, and can spread
rapidly and establish new populations in areas where they are not native. This
can cause problems for native plants and wildlife, as well as for agriculture
and other industries.
Difficulty in removal: Thistles have deep taproots that make them difficult to
remove, especially if they are well-established. In addition, cutting or mowing
the plants can stimulate new growth and make the problem worse.

• Black medic (Medicago
lupulina) is an annual
weed species that
belongs to the Fabaceae
or legume family. It is
also commonly known as
black clover, hop clover,
or yellow trefoil.

• Black medic typically
grows in gardens, lawns,
roadsides, and other
disturbed areas. Black
medic can be an indicator
of low fertility or poor soil
conditions, as it is able to
thrive in soils that are low
in nitrogen.

• The seeds of
black medic can
remain viable in
the soil for up to 5
years, so it is
important to be
persistent in
control efforts.

• The plant grows up to 60 cm
tall and has a taproot system.
The leaves are trifoliate,
meaning they have three
leaflets that are rounded or
oval in shape and usually have
a small notch at the tip. The
flowers are small and yellow,
arranged in compact clusters
at the end of the stems. The
fruit is a small pod that
contains one or two seeds.

• Black medic can be used as a forage
crop for livestock, as it is high in protein
and can be grazed or cut for hay.
• Black medic can be confused with other
clover species, such as white clover
(Trifolium repens). One way to tell them
apart is by the size of the flowers - black
medic has smaller flowers than white
clover.

• Control of black medic can be achieved through several methods:
• Cultural Control:
• Maintaining a dense, healthy lawn or garden can help to prevent
the establishment of black medic. This can be achieved by proper
fertilization, irrigation, and mowing.
• Mechanical Control: Hand-pulling or hoeing can be effective for
small infestations of black medic. However, it is important to
remove the entire plant, including the taproot, to prevent
regrowth.
• Chemical Control: Herbicides can be effective for controlling black
medic. Selective herbicides, such as 2,4-D or dicamba, can be
applied to lawns to kill the weed without harming desirable plants.
Non-selective herbicides, such as glyphosate, can be used to
control black medic in garden beds or other non-lawn areas.
This Photo by Unknown author is licensed under CC BY-SA-NC.

• Henbit (Lamium
amplexicaule)
• It is native to Europe
and Asia, but has now
become naturalized in
many parts of the world,
including North America.
Henbit is often found in
lawns, gardens,
agricultural fields, and
other disturbed areas.
Henbit (Lamium
amplexicaule) is a
common winter annual
weed that belongs to the
mint family (Lamiaceae).

• The stem of henbit is square-
shaped and can grow up to 12
inches in height. The leaves
are arranged oppositely along the
stem and are typically round to
heart-shaped, with a
slightly toothed edge. The leaves
can range in size from 1/2 to 2
inches in diameter. The flowers
are pink to purple in color, and are
arranged in whorls at the top of
the stem. The uppermost leaves
may be more pointed and have a
reddish tinge. The stem and leaves
of henbit can have a purplish
coloration.​

• Henbit seeds are small and
can remain viable in the soil
for up to 3 years. The seeds
are dispersed by wind,
water, and other means,
allowing henbit to spread
rapidly throughout an area.

• Henbit flowers from late
winter to early summer,
producing pink to purple
flowers that are arranged
in whorls at the top of the
stem. The flowers are
tubular in shape and can
be up to 1/2 inch in
length. Each plant can
produce numerous
flowers, which can lead to
prolific seed production.

• Cultural control methods for henbit include maintaining a healthy lawn or
garden through proper nutrition and irrigation, as well as regular mowing or
removal of weeds before they produce seed. Mechanical control methods
include hand-pulling or hoeing small infestations, or mowing larger
infestations before they produce seed.
• Mechanical control: Hand-pulling or hoeing can be effective for small
infestations of henbit. For larger infestations, use a rotary or string trimmer
to mow down the plants before they produce seeds.
• Chemical control: Pre-emergent herbicides can be applied in the fall to
prevent henbit seeds from germinating in the spring.
• Post-emergent herbicides can be applied in the spring to control henbit
plants that have already emerged.
• It is important to read and follow all label instructions when using
herbicides.

• Oxalis stricta, commonly
known as common yellow
woodsorrel or simply
oxalis, is a common weed
found in lawns, gardens,
and other disturbed areas
throughout much of the
United States and Canada.
It is a member of the
Oxalidaceae family and is a
perennial plant that can
grow up to 12 inches tall.

• Oxalis has trifoliate
leaves that resemble
clover, with each leaflet
measuring around 1 inch
across. The leaves are
light green in color and
have a sour taste when
eaten. The plant
produces small yellow
flowers with five petals
that bloom from May to
August, and it produces
small seed pods that are
dispersed by exploding
when ripe.

• Seeds: Oxalis produces small seed pods that are about 1/4 inch long.
The pods are initially green and turn brown as they mature. When the
pods are ripe, they explode and scatter the seeds up to several feet
away.

• Oxalis prefers moist, well-drained soil and is often found in lawns, gardens,
fields, and other disturbed areas. It can also grow in shady areas, but it
thrives in areas with plenty of sunlight.
• Oxalis is a low-growing plant that can form dense mats of foliage if left
unchecked. It spreads by seed and by runners (stolons) that root at the
nodes and produce new plants.

• The leaves of Oxalis are
trifoliate, meaning they
have three leaflets. Each
leaflet is heart-shaped and
has a notched tip. The
leaves are typically light
green in color and have a
sour taste when eaten.

• Hand-pulling or digging out oxalis
can be effective, especially when the
plants are young and the roots are
shallow. Be sure to remove all of the
roots, as even a small piece left
behind can grow into a new plant. This
can be done with a hoe or trowel.

Oxalis stricta is a common and widespread weed that can be difficult
to control once it becomes established. However, with proper
management techniques, it can be kept under control and prevented
from spreading.
A healthy lawn that is well-maintained and regularly fertilized will be
better able to compete with weeds like oxalis. Mowing regularly and at
the proper height for your grass type can also help to prevent weeds
from becoming established.

• The proper mowing height for your lawn depends on the type of grass you
have. Here are some general guidelines for the most common types of
grass:
• Bermuda grass: Mow at a height of 1/2 to 1 inch (1.3 to 2.5 cm).
• Zoysia grass: Mow at a height of 1/2 to 1 inch (1.3 to 2.5 cm).
• Kentucky bluegrass: Mow at a height of 2 to 2 1/2 inches (5 to 6.4 cm).
• Fine fescue: Mow at a height of 2 to 3 inches (5 to 7.6 cm).
• Tall fescue: Mow at a height of 3 to 4 inches (7.6 to 10.2 cm).
• When mowing, remember the "one-third rule" – never remove more than
one-third of the grass blade at a time. This will help promote healthy
growth and prevent damage to your lawn. Additionally, be sure to keep
your mower blades sharp to ensure a clean cut, and vary the direction in
which you mow to prevent grass from bending in one direction.
This Photo by Unknown author is licensed under CC BY-NC.

• Herbicides can be effective in controlling oxalis, but they should be
used with caution and according to the label instructions. Glyphosate is
a non-selective herbicide that can be used to kill oxalis and other
weeds, but it will also kill any other plants it comes into contact with. A
selective herbicide that targets broadleaf weeds, such as 2,4-D or
dicamba, can also be used to control oxalis without harming grasses.

• Red sorrel, also
known as sheep
sorrel or field
sorrel, is a
common weed
that belongs to
the genus Rumex
and the family
Polygonaceae.

Appearance: Red sorrel is a small,
herbaceous perennial plant that typically
grows to about 30 cm (12 inches) in
height. It has arrow-shaped leaves with a
distinct reddish tint, and produces small
clusters of greenish flowers on tall stalks.
Habitat: Red sorrel is commonly found in
open fields, meadows, and other
disturbed habitats. It prefers well-drained
soils and full sunlight.

Arrow-shaped: The leaves of red
sorrel are arrow-shaped or
lanceolate, meaning that they are
longer than they are wide and taper
to a point at the tip. The base
of the leaf may be slightly heart-
shaped. Reddish tint: The leaves of
red sorrel are typically green with a
reddish tint, especially near the base
of the leaf.
Smooth margins: The edges of the
leaves are typically smooth, without
any teeth or lobes.

Taproot: Red sorrel has a taproot, which means that the main root grows
straight down into the soil. However, the taproot is relatively small and
shallow compared to other tap rooted plants.
Fibrous roots: In addition to the taproot, red sorrel also produces many
fibrous roots that spread out horizontally from the base of the plant.
These roots help to anchor the plant in the soil and absorb water and
nutrients. Rhizomes: Red sorrel can also produce rhizomes,
which are horizontal stems that grow underground and
produce new plants. This can help the plant to spread quickly
in suitable habitats. Adaptation to poor soils: Red sorrel is adapted
to grow in poor soils with low fertility, which is reflected in the size and
structure of its roots. The small taproot and extensive fibrous root system
help the plant to access nutrients and water in the soil.

Red sorrel seeds are
the small, dark-colored
seeds produced by the
red sorrel plant (Rumex
acetosa), also known as
sour dock or garden
sorrel.

Invasive potential: While
red sorrel is not considered
invasive in its ​native range,
it can become weedy and
spread quickly in areas
where it is introduced. It
can compete with native
plants and ​reduce
biodiversity in these areas.

• Purslane (Portulaca
oleracea) is an annual
succulent herb that
belongs to the
Portulacaceae family. It
is a low-growing plant
that can grow up to 40
cm tall and spread up to
60 cm wide.

• Purslane has a thick, fleshy stem
that is reddish-green in color and
can have a slightly reddish hue. The
plant has oval-shaped leaves that
are smooth, thick, and succulent.
The leaves are generally 1-2 cm
long and 0.5-1.5 cm wide and can
vary in color from green to reddish-
green. The leaves are arranged
alternately along the stem and
have a shiny appearance.

• Purslane produces
small yellow flowers that
are about 6 mm in
diameter. The flowers
bloom in midsummer
and continue until the
first frost. The fruit of
purslane is a small
capsule that contains
numerous tiny, black
seeds. The seeds can
remain viable in the soil
for up to 40 years,
making purslane a
prolific self-seeder.

• Purslane has a shallow root
system, which means that it
can be easily pulled up by
hand. However, if left to grow
unchecked, it can become
difficult to control.
• Purslane is a hardy and
resilient plant that can grow in
a wide range of conditions. It
prefers full sun but can tolerate
partial shade. It can grow in
poor soil and is drought-
tolerant, making it an ideal
plant for arid regions.

Cultural control: One way to prevent purslane from spreading is to maintain
a healthy garden environment. This can include practices such as planting
dense groundcovers to suppress weed growth, mulching to conserve soil
moisture and prevent weed germination, and using drip irrigation to
minimize water waste.
Mechanical control: Purslane can be manually removed by hand-pulling or
hoeing. Be sure to remove the entire plant, including the roots, to prevent
regrowth. If you plan to compost the plants, be aware that the seeds can
remain viable even after the plant has been uprooted.
Chemical control: If purslane is particularly widespread or difficult to control
manually, herbicides may be necessary. Glyphosate is a commonly used
herbicide for purslane control, although other herbicides may also be
effective. Be sure to read and follow all label instructions carefully, as
herbicides can be harmful to other plants and the environment if used
improperly.

• Prevention: Because
purslane is such a prolific
seed producer,
preventing seed
production is key to
preventing its spread.
Remove purslane plants
before they flower and
set seed. Be aware that
purslane seeds can
remain viable in the soil
for many years, so it may
be necessary to monitor
and manage purslane for
several growing seasons
to fully eradicate it.

Prostrate Knotweed
(Polygonum aviculare)
• Polygonum aviculare, commonly
known as prostrate knotweed. The
plant typically grows low to the ground,
forming a mat-like groundcover that
can reach up to 50 cm in diameter. Its
leaves are alternate, oval-shaped, and
have a pointed tip. They are usually
green but may sometimes have a
reddish or purplish tinge. The stem of
the plant is thin, wiry, and reddish-
brown, and it branches out to form a
dense, tangled mass.

• The flowers of the prostrate
knotweed are small, pinkish-
white or greenish-white, and
arranged in clusters on the
tips of the stems. They
bloom from June to
September, and each flower
produces a small, triangular,
dark brown or black seed.
The seeds are enclosed in a
shiny, dark brown, three-
sided nutlet that is
approximately 2-3mm in size.

• Prostrate knotweed is
an incredibly adaptable
plant and can thrive in a
variety of environments,
including disturbed sites,
lawns, gardens, fields,
and waste areas. It is
also tolerant of a wide
range of soil types and
can grow in both dry and
wet conditions.

• Prostrate knotweed is
considered an invasive
weed due to its nature
and ability to
outcompete native
vegetation. It can reduce
the productivity of
agricultural fields and
interfere with the
growth of desirable
plants in gardens and
landscapes.

• Remove knotweed plants
before they go to seed.
• Avoid disturbing soil where
knotweed seeds may be
present. Knotweed seeds can
remain viable in soil for up to
20 years, so disturbing soil in
areas where knotweed has
grown in the past can cause
seeds to germinate.
• Keep an eye out for
knotweed seedlings. If you
see knotweed seedlings,
remove them immediately to
prevent further spread.

Quackgrass (Elymus repens)
• Quackgrass, also known as couch grass or
quick grass, is a perennial grass species
scientifically named Elymus
repens. Quackgrass can grow up to 3 feet
tall and has an extensive system of
underground stems or rhizomes that can
reach up to 8 feet long. These rhizomes are
thick, white, and fleshy, with nodes from
which roots and shoots emerge.

• The leaves of quackgrass are long and narrow, typically 4 to 10
inches long and 1/4 to 1/2 inch wide. They have a rough texture, are
bluish-green in color, and have prominent veins.
• The plant's stems are hollow and can be easily bent, making it
flexible and difficult to pull out of the ground.

• Quackgrass has a distinctive,
unpleasant odor when crushed
or bruised. The seeds
of quackgrass are flat and
oblong, with a shiny
surface and a pale yellow or
light brown color.

• Quackgrass can spread
quickly and aggressively,
forming dense mats that
can outcompete other
plants for resources and
space.
• The rhizomes of
quackgrass can
penetrate deep into the
soil, making it difficult to
completely remove the
plant.

• Quackgrass is a
perennial plant, which
means that it can survive
for multiple years. It
reproduces through both
vegetative and sexual
means. The rhizomes of
quackgrass can sprout
new plants, and the
seeds can germinate to
produce new plants as
well. The plant begins to
grow in early spring and
can continue to grow
until late fall or early
winter.

• Quackgrass can be challenging to control because of its
extensive root system and ability to regenerate from small
fragments of rhizomes. Cultural and chemical control methods
are available to control the spread of quackgrass. Culturally,
hand-pulling, mowing, and tilling can be effective but require
regular maintenance. Chemical control methods include the
use of herbicides such as glyphosate, which is effective in
killing the plant down to its roots. However, repeated
applications may be necessary to completely eradicate
quackgrass.

• Shepherd's purse, scientific name Capsella
bursa-pastoris, is an annual or biennial
herbaceous plant that belongs to the
mustard family (Brassicaceae).
• The plant has a small rosette of basal
leaves at the base of the stem, which can
grow up to 30 cm (12 inches) tall. The leaves
are green and spade-shaped, with deeply
lobed margins. The stem is erect, branched,
and hairy, with small, white, four-petaled
flowers that bloom from May to September.
The flowers are arranged in a loose raceme
and are less than 1 cm (0.4 inches) across.
The fruit is a small, heart-shaped capsule
that contains numerous tiny seeds.

• Shepherd's purse is a common
weed that grows in disturbed
areas such as fields, gardens,
roadsides, and waste areas. It
can grow in a wide range of
soils and can tolerate a variety
of environmental conditions.
The plant is hardy and can
survive in cold and dry
conditions.

• Shepherd's purse can
be considered a weed
pest of lawns, especially
if it is allowed to grow
unchecked. The plant
can quickly colonize
disturbed areas,
including lawns, and its
small size and prolific
seed production make it
difficult to control.

• Here are some tips for dealing with shepherd's purse seeds:
• Remove plants before they go to seed. This is the most effective way
to prevent the spread of shepherd's purse seeds.
• Hand-pull shepherd's purse plants. If you only have a few shepherd's
purse plants, you can hand-pull them to remove them from your lawn
or garden. Be sure to pull the entire plant, including the roots.
• Mow your lawn regularly. Mowing your lawn regularly can prevent
shepherd's purse plants from going to seed.
• Use a pre-emergent herbicide. Pre-emergent herbicides can prevent
shepherd's purse seeds from germinating. Apply the herbicide in early
spring before the seeds have a chance to germinate.

Mechanical control: The most straightforward way to control Shepherd's
purse is to pull or hoe it out manually. This method is best suited for small
infestations, and care should be taken to remove the entire root system to
prevent regrowth.
Mulching: Mulching can be an effective control method, especially in
garden beds. A layer of organic mulch, such as leaves or straw, can be
placed over the soil to prevent seeds from germinating and to smother
existing plants.
Herbicides: Herbicides can be effective at controlling Shepherd's purse,
but care should be taken to choose a product that is appropriate for the
specific site and to follow the manufacturer's instructions carefully.
Glyphosate, 2,4-D, and dicamba are some common herbicides that can
be used for control.

• Annual bluegrass is a winter annual
weed that has light green leaves and
small seedheads. It can grow up to 8
inches tall and forms dense mats.
Annual bluegrass (Poa annua) is an
annual weed that is native to Europe
but is now found throughout much of
the world. It is a member of the
Poaceae family and is known for its
small size and bright green color.
Annual bluegrass is often found in
lawns, golf courses, and other
managed turf areas, as well as in
agricultural fields and other
disturbed habitats.

• The leaves of annual
bluegrass are flat and narrow,
with a boat-shaped tip and a
glossy texture. The leaves are
typically less than 1/8 inch
wide and can grow up to 6
inches long. The stems of the
plant are thin and can grow up
to 12 inches tall, with a cluster
of small, white flowers at the
top of the stem. Annual
bluegrass is typically a prolific
seeder, producing hundreds of
seeds per plant that can
remain viable in the soil for
several years.

• Annual bluegrass is a
cool-season grass that
germinates in the fall and
grows actively throughout
the winter and spring. It
prefers moist, well-drained
soil and can tolerate a
wide range of
temperatures, from below
freezing to over 100°F.
Annual bluegrass is often
found in areas with low
soil fertility, and it can
outcompete other
turfgrass species under
these conditions.

• Maintaining a healthy, well-fertilized lawn can help
to prevent annual bluegrass from taking hold in the
first place. Proper mowing, watering, and fertilization
can help to keep the grass thick and healthy, reducing
opportunities for weeds to take hold. Chemical
herbicides can be effective in controlling annual
bluegrass, but should be used with caution as they can
harm desirable plants and can have negative impacts
on the environment. Pre-emergent herbicides, such as
prodiamine or dithiopyr, can be applied in the fall to
prevent annual bluegrass seeds from germinating.
Post-emergent herbicides, such as glyphosate or
dicamba, can be effective in controlling established
plants.

This Photo by Unknown author is licensed under CC BY-SA.

• In conclusion, weed
control is an essential
aspect of maintaining a
healthy lawn and
garden. Weeds compete
with desirable plants for
nutrients, water, and
sunlight, and can quickly
take over if left
unchecked. The most
effective way to control
weeds is through a
combination of
preventative measures
and active management.
This Photo by Unknown author is licensed under CC BY-SA-NC.

• Preventative measures include
improving soil conditions, maintaining
healthy plants, and using proper
planting techniques to prevent weed
growth. Active management includes
hand-pulling weeds, mowing lawns
regularly, using herbicides, and
properly disposing of weeds and their
seeds. This Photo by Unknown author is licensed under CC BY-NC-ND.

• It's important to choose the right
herbicide for the type of weed
you're dealing with, and to follow
label instructions carefully to
prevent damage to desirable plants
and the environment. Additionally,
taking steps to prevent the spread
of weed seeds is crucial, as many
weed seeds can remain viable in
soil for years, and can quickly
germinate when conditions are
favorable.
This Photo by Unknown author is licensed under CC BY.

• By taking a
proactive approach to
weed control, you
can maintain a
healthy lawn and
garden that is free of
invasive weeds and
filled with vibrant,
healthy plants.

Ohio State Weed Lab , The Ohio State University, Bugwood.org
Jill Swearingen, USDI National Park Service, Bugwood.org
Charles T. Bryson, USDA Agricultural Research Service, Bugwood.org
Michael Shephard, USDA Forest Service, Bugwood.org
Mary Ellen (Mel) Harte, Bugwood.org
John D. Byrd, Mississippi State University, Bugwood.org
Steve Dewey, Utah State University, Bugwood.org
Ken Chamberlain, The Ohio State University, Bugwood.org
Barbara Tokarska-Guzik, University of Silesia, Bugwood.org
Lynn Sosnoskie, University of Georgia, Bugwood.org
L.L. Berry, Bugwood.org
Howard F. Schwartz, Colorado State University, Bugwood.org
Rebekah D. Wallace, University of Georgia, Bugwood.org
David Cappaert, Bugwood.org
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Forest and Kim Starr, Starr Environmental, Bugwood.org
Whitney Cranshaw, Colorado State University, Bugwood.org
Bruce Ackley, The Ohio State University, Bugwood.org
Rob Routledge, Sault College, Bugwood.org
Theodore Webster, USDA Agricultural Research Service, Bugwood.org
Elizabeth Bella, AECOM, Bugwood.com
Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org
Richard Gardner, Bugwood.org
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
AMERICAN PEST CEUS
THANKS ALL OF THE
PHOTOGRAPHERS
WHO ALLOWED USAGE
OF THEIR IMAGES FOR
THIS COURSE

The use of trade names in this publication is solely for the
purpose of providing specific information.
American Pest CEUS does not guarantee or warranty the
products named, and references to them in this
publication do not signify our approval to the exclusion of
other products of suitable composition.
All chemicals should be used in accordance with
directions on the manufacturer's label. Use pesticides
safely.
Read and follow directions on the manufacturer's label.

Thank you for choosing
American Pest CEUs
You have completed the course
Please proceed to the quiz