1. Ecolawns for the Pacific Northwest
Tom Cook
OSU Horticulture
2007
2. What should lawns be?
• Do all lawns have to be pure grass?
• Do lawns have to be a mono-culture?
• Are there good broadleaf weeds?
• Are there niches for different kinds of
lawns?
• Who decides what is appropriate?
3. The evolution of ecolawns
After looking at lawns throughout the Pacific Northwest west of the Cascades for many years, it
has become clear to me that most homelawns, parks, cemeteries, school grounds, etc. are in no way
pure stands of grass. Most are a mixture of a fairly wide array of grasses and a fairly predictable
list of dicot plants (broadleaf weeds) that are well suited for the conditions under which the lawns
are being maintained. In the worst case scenario, the result is an ugly, weedy mess. Often, however,
I see very attractive and apparently stable mixtures of plants that seem to perform well with
minimal water, fertilizer, and mowing.
The idea of ecolawns is to try to simulate this ultimate climax vegetation to produce a lawn that is
functional, reasonably attractive, and requires fewer rather than more inputs to produce an
acceptable lawn.
There are many roadblocks in pursuing this goal. The biggest one (as noted on the slides that follow) is
that many desirable components for an ecolawn are not in the commercial trade. The ecolawns
described below are based on components that are available for purchase. With concerted effort, a
host of new species may one day be available, resulting in much more sophisticated mixtures that are
truly self sustaining.
4. Naturally occurring ecolawns
This is an old lawn that has evolved on its own to a fairly steady state climax. It is characterized
by partial shade, heavy soil, excess winter moisture, low fertility, and regular mowing with clippings
returned. The components include bentgrasses, rough bluegrass, white clover, and Veronica
chameadrys. All components are well suited to the site and tolerant of mowing.
T Cook photo
5. Veronica chameadrys ecolawn flowering in spring
All Veronicas have beautiful flowers in
spring. The rest of the year the plants
blend in nicely with the grass to produce
a lawn that is easy to care for.
T Cook photo
6. Naturally occurring bentgrass/lawn violet ecolawn
Lawn violets are another plant well suited to ecolawns. They don’t blend as well with
grass as some other plants, but the flowers more than make up for that in early spring.
Like many compatible lawn plants violets can self seed and spread vegetatively.
T Cook photo
7. Naturally occurring bentgrass/ Galium ecolawn
One of the most intriguing plants with potential as part of an ecolawn is Galium verum.
As this photo shows, Galium is extraordinarily drought tolerant and can stay green
without any irrigation at all in the Willamette Valley of Oregon. It mixes well with
grass and looks very much like a conventional lawn for most of the year. It produces
small yellow flowers in summer, but they are not very showy. It’s weak link is poor
seed production. It can spread by seed or vegetatively by rhizomes. If seed were
available, it would be a great addition to an ecolawn mix.
T Cook photo
8. This site is extremely dry with only False dandelion and Galium verum
managing to stay green by late summer. The grass in the foreground is
Rat-tail fescue, which is a winter annual. Galium verum typifies desirable
plants that are not commercially available. T Cook photo
9. This stand of Galium is dense and green even without any irrigation. The
yellow flowers develop in summer, but rarely cover the entire stand.
Lady’s Bedstraw, Galium verum
T Cook photos
10. Constructed Ecolawns
1.Base of Perennial ryegrass
2.Common yarrow
3.Clovers
4.English Daisies
5.Others?
The first step in developing commercial ecolawn mixes is to find dicot and grass components that can be
purchased in the trade. Our initial trials were based on the ingredients listed above.
11. Common Yarrow Achillea millefolium
Yarrow is fairly common in lawns and gardens where it has demonstrated excellent drought
tolerance. It blends well with grass and is well adapted to regular mowing. Best of all it is
very persistent.
T Cook photo
12. Strawberry clover Trifolium fragiferum
In our early trials we used a variety of Strawberry clover called ‘Fresa’ developed at New
Mexico State University. Shown here it is dense and persistent and well adapted to mowing.
It has excellent drought tolerance. Unfortunately, it was not a commercial success due to
poor yields in production fields. Now most strawberry clovers used in ecolawn mixes come
from the forage trade. They tend to be ranker growing, but still work okay.
A new micro-white clover is now available that will likely fill the void created by loss of
‘Fresa’ strawberry clover.
T Cook photo
13. English daisy Bellis perennis
English daisy is a common component of drought stressed
lawns throughout western Oregon and Washington. The wild
types are very hardy and tolerate summer drought by going
dormant. They can spread by seed or vegetative propagation.
For our mixes we have had to use daisies out of the flower
trade. These are not as hardy and the stand tends to fade out
over a three to five year period after planting. T Cook photo
15. Yarrow and White clover in summer
Clver and yarrow are the most drought hardy components in commercial mixes. They
work well in summer to obscure the now dormant ryegrass, while presenting a green
cover. Normally, we irrigate once per month starting in mid June.
T Cook photo
17. Performance at Corvallis on clay soil
Mowing goal: 1 per 3 wks 2” with mulching rotary
Mowing reality: 1 per 2-4 wks
Irrigation goal: 1 per mo. June, July, Aug, Sept 4 total
Irrigation reality: 2-4 total per year
Pest control goal: no treatments
Pest control reality: no treatments on clean sites
one treatment sequence in year two on dirty sites
18. Corvallis
4 irrigations
per summer
Mowed
every 3 weeks
Wilsonville
No irrigation
3 mowings?
With modest water in summer ecolawns
have stayed green. Without any water
they go dormant like most other lawns.
T Cook photos
19. Ecolawns in practice
This is a commercial mixture planted around the renovated Weatherford Hall on the OSU
campus. This is typical of a young ecolawn in mid spring in the Willamette Valley of Oregon.
T Cook photo
20. Ecolawns in practice
Spring is the time to see the flowers. In summer, ecolawns look
more like conventional grass lawns from a distance.
21. Ecolawns in practice
After nearly a month without water, the grass lawn planted to hard fescue is partially dormant and
generally unattractive. The ecolawn mixture dominated by yarrow and clover still looks green. This is
the major strength of the ecolawn mixtures, the ability to look green under droughty conditions.
22. Where do ecolawns fit in the big picture?
So far we have done little more than assemble mixtures based on plants we thought might work
and knew were commercially available. The interest on the part of the public has been surprisingly
strong and has come from all over the USA.
There are obvious short comings with current mixes. They contain a limited number of species, the
daisies tend to disappear over time, users don’t seem to understand that reduced input doesn’t mean
no input, etc. Still, people do continue to plant them and many are very pleased with the results.
To move beyond this ‘first try’ stage, a lot of work needs to be done. We need to continue searching
for new and better components. We need to figure out how to grow and produce seed from the
promising components and the production process needs to be commercialized.
Since ecolawns need to be regionally specific if they are to persist over time, researchers in other
parts of the country need to begin the process of evaluating potential mixes for their regions. Before
that can happen, turf people have to buy into the concept as one more piece of the puzzle as far as
sustainable lawns are concerned. Right now there is a powerful bias toward pure grass turf in the
turf research community and the public.
I don’t ever see ecolawns replacing conventional grass lawns but I hope to see more options for lawns
than we have at the present time. My goal is to see people have acceptable lawn groundcovers that
don’t require intensive applications of water, fertilizer, or pest control products. Expanding our concept
of lawns beyond just grass may increase the chances of that happening.
