2. Seminar recommendations
Based on current, peer-reviewed
science
Include materials certified as OMRI
Include materials registered *only* for
home garden use in Washington state
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
3. Modes of action
Preventative*
Feeding
Egg laying
Spore and seed germination
Curative
Suffocation
Starvation
Disruption of biochemical
and/or physiological processes
*must be able to predict
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
4. Preventative - feeding
Odor
Essential oils
Neem
Taste
Garlic (lectin)
Neem
Pyrethrin
Touch
Horticultural oils
Kaolin
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
6. Curative - suffocation
Horticultural oils
Kaolin – fine particle clay
Diatomaceous earth – fine particle silica
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
7. Horticultural oils
Includes those made from plants
(seeds, leaves, bark) and
petroleum
Most effective on soft bodied
insects
May suppress disease
Must apply before symptoms
appear
Can be phytotoxic
Can injure beneficials
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
8. Curative - starvation
Stomach poison
Bacillus thuringiensis (Bt)
Pyrethrins
Spinosad
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
9. Ingestible insecticides
Includes Bt, neem, pyrethrins and spinosad
More targeted to pest species
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
10. Curative - disruption
Weed/weed seedling death
Maize gluten meal, vinegar
Insect cuticle abrasion
Diatomaceous earth, kaolin, potassium laurate (soap)
Insect growth and development interference
Neem, nematodes (microscopic worms)
Insect enzyme poisoning
Copper octanoate
Insect neurotoxin
Pyrethrins, spinosad
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
11. Pesticide realities
Pesticide registration does not include
product efficacy testing
Success in lab testing does not guarantee
success in the field
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
12. Maize gluten meal
High nitrogen byproduct of corn
milling
Registered herbicide
for turf
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
13. MGM effectiveness on crab grass control
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
14. MGM impact on crab grass root growth
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
15. Fungicides
Bacillus subtilus
Canola, corn, jojoba and sesame oils
Copper octanoate
Garlic oil
Kaolin
Potassium bicarbonate
Sulfur
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
16. Herbicides
Cinnamon and lemongrass oils
Clove and eucalyptus oils
Herbicidal soap
Limonene
Maize gluten meal
Soybean oil
Vinegar (20% acetic acid)
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
17. Insecticides
Bt, nematodes and spinosad
Canola, cottonseed, mineral and sesame oils
Clove and mint oils
Diatomaceous earth and kaolin
Garlic oil
Neem
Nematodes
Potassium laurate
Pyrethrins
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
18. Essential oils
Volatile oils (fragrant)
Work best in enclosed areas
Can be phytotoxic
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
19. Essential oils for homeowner use
Insects/microbes:
cinnamon, clove, rosemary
and thyme mixture
Insects/microbes: neem oil
Ants: clove oil, mint oil
Roaches: mint oil
Deer: black pepper oil, garlic oil
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
20. Popular mixed essential oil
products
“…blending extracts…does not ensure enhanced
biological activity.”
“…numerous plant-derived essential oil
products…have not been subject to rigorous
evaluation.”
“Products vary in their
effectiveness against certain
arthropod pests…and are
phytotoxic.”
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
21. Pesticide realities
All registered pesticides are tested to
determine toxic effects on people and on
ecosystems
Home remedies and other unregistered
pesticides can be harmful to people,
pets and the environment
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
22. Potential drawbacks –
big and small
Natural does not equal “safe”
Lead arsenate used as a pesticide until 1988
Nicotine and rotenone used as insecticides until
about 8 years ago
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
23. Potential drawbacks –
big and small
Broad spectrum pesticides can kill
beneficials, other non-target organisms
More frequent application is often
necessary with organic pesticides
Some products phytotoxic
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
25. Potential drawbacks –
big and small
Any improperly used
pesticide can
contaminate the
environment
Any improperly used
pesticide can create
resistant pest populations
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
DDT
resistant
insects
Roundup
resistant
weeds
27. Tips for creating naturally
healthy gardens and landscapes
Purchase disease-resistant plants
Select plants adapted to your site
conditions
Keep plants happy – healthy plants are more
resistant to pests and disease
Increase your plant palette – a more
biodiverse garden is more resistant to pests
and disease
Maintain good garden hygiene by removing
infected plant tissues
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
29. Go back to college with the Garden Professors
http://blogs.extension.org/gardenprofessors/
Dr. Linda Chalker-Scott
WSU Extension Urban Horticulturist
