We've all seen it, in our visits to friends and relatives who live in the 'burbs. Astro-turfish lawns consisting of millions of soldier-straight, identical blades. Stern injunctions to the children and teenagers: no frisbee, no football, please. ChemLawn trucks at the curb.
The American fascination with the lawn is, according to writers Priscilla Williams and Michael Nadeau, a product of the mid-twentieth century: "It wasn't until the advent of selective herbicides about 50 years ago that a lawn consisted of only grasses. Before that, any plant that lived under the mower blade was considered 'lawn.'"
If the only difference between an organic lawn and a chemically supported lawn were aesthetic, a live-and-let-live attitude might be the wisest course. But since evidence is mounting that these lawns can hurt children, pets, and sensitive ecosystems, maybe it's time to start proselytizing…or at least to demonstrate to our neighbors, by example, that a natural lawn can be beautiful.
NOFA Leads the Way
The Northeast Organic Farming Association (NOFA) formed its Organic Land Care Program in 1999. At the heart of this program is a certification process for landscape professionals, and a comprehensive set of standards for maintaining non-agricultural landscapes. The NOFA organic land care standards can be found on the web at http://www.organiclandcare.net.
The NOFA standards emphasize that healthy soil is the fundamental basis of an organic lawn. Test your soil before developing a plan for your yard: a professional soil analysis will yield far more useful and accurate information than can be gleaned by the homeowner who uses kits available in garden stores.
Compost is key. Good compost should be used—many practitioners recommend against the use of household compost on lawns, as it tends not to represent the proper nutrient mix. Compost is especially important if chemicals have been used on the lawn, as it re-establishes important microorganisms that pesticides and synthetic fertilizers may have killed.
In New England, we tend to have acidic soils. Lawns do best where the underlying soil has a pH of 6.5 or higher. There are several types of lime that can be applied in the late fall—use Aragonite or Dolomitic lime where magnesium levels are already high.
If your soil is very low in nitrogen, NOFA recommends applying an organic fertilizer in the fall. Rock phosphate can also be added in the fall to boost phosphorous, which is important for root health. Rock dust can be spread any time of year to add trace minerals.
Mowing technique matters: practitioners recommend mowing high with a sharp blade. Aeration can be encouraged with earthworms, or performed manually—some gardeners do their work in spiked clogs. Finally, proper watering is very important. Water deeply, instead of often, wetting the entire root zone. Note that healthy soil with sufficient organic matter will do more to help your lawn through drought than any irrigation system.
In choosing plants and seeds, biodiversity is essential. Bluegrasses, ryegrasses, fescues and clovers can coexist in your organic lawn. For those who love flowers, Peaceful Valley Farm and Garden Supply (http://www.groworganic.com) offers an herbal lawn mix that contains Roman chamomile, English daisy, snow-in-summer, sweet alyssum, bird's foot trefoil, baby blue eyes, blue pimpernel, creeping daisy, pinks, German chamomile, creeping thymeand and Johnny-jump-up.
What about weeds and pests?
Bernadette Giblin, proprietor of Safeground Organic Lawncare in Northampton, notes that weeds are a symptom of troubled soil. "Low pH and soil compaction are the leading cause of weed growth," she advises. Williams and Nadeau concur. "Often excess weeds are a symptom of poor soil, a flag that lets you know a pH adjustment is needed," they write. "Healthy turf and weeds cannot coexist. The turf will shade and crowd out the weeds."
Soft, low-growing plants such as violets, thyme, chamomile, and even ground ivy are tolerated, or even encouraged, in most organic lawns. But what about large sections of lawn where noxious weeds, such as plantain and crabgrass, have taken over? In such cases, NOFA recommends the application of corn gluten meal "before weeds emerge, usually between forsythia and lilac bloom." Corn gluten meal prevents the germination of weed seeds.
There are several caveats: corn gluten meal contains organic nitrogen, which should be accounted for in the overall management of your lawn. If you spread corn gluten after weeds have germinated, you'll simply be fertilizing them. Corn gluten treatments can leave bare spots. In such cases, NOFA recommends spot-seeding with an annual rye grass, mixed with compost, until a perennial lawn seed mixture can be established in the fall.
A spray bottle full of household vinegar can also be used for spot weed control, especially where weeds emerge between the cracks of terraces and walkways. Organic herbicides made from the essences of vinegar and lemon juice or potassium salts are available commercially as well. Of course, the old-fashioned practice of manual weeding is still an effective practice. Be sure to pull up the whole root, and to re-seed or replace the divot with desired plantings.
White grubs—the larvae of several types of common beetles—can spell trouble for a lawn. Grubs start feeding on the root systems of grass upon hatching in late July. By October, root consumption is at its highest level. Winter does not kill the grubs—they burrow deep, re-emerge in the spring, and start feeding.
Two biological controls for grubs are allowed under the NOFA standards: insect-attacking nematodes, and arthropod pathogens such as milky spore bacteria. Hand-picking and killing live beetles can go a long way to reduce egg-laying and grub populations. Attracting birds, toads, lizards, garden snakes and bats to your property will also help control these pests.
Fleas, ticks and mosquitoes can be discouraged with garlic oil. Garlic oil concentrate can be purchased in garden stores, or you can make your own by crushing a handful of garlic cloves and soaking them in a gallon of water for a day. Strain out the garlic before spraying your property. Repeat every three to four weeks.
Ultimately, your yard is meant to be used. You'll feel good hosting your summer party knowing that your lawn is durable, healthy, benign and beautiful.