Lawns

If you want someone else to take care of your lawn and garden, don’t just take their word for it if they say their products and practices are “safe” or “environmentally sound.” Instead, ask lots of specific questions. Click on the link for some tips from Beyond Pesticides.

Help Your Grass Kick Its Chemical Dependency

Caring for an organic lawn is not just a matter of substituting organic products for chemical ones. Soil health and horticultural techniques are key. Your goal is to keep your grass as lush as possible, so it not only looks lovely, but also crowds out the weeds.

You start with healthy soil, rich in organic matter and teeming with worms and microorganisms. The grass roots grow deep, and the grass leaves grow strong. You water deeply but infrequently; those long grass roots can drink for a long time after a watering while weed seedlings on the surface dry out. And you mow high, so the grass shades out weed seedlings.

A big caution: If you’re moving from chemical to organic care, don’t expect instant results. It can take months or even years to build optimum soil and plant health.

Tips

  • Add organic matter. Compost can improve the texture of any soil, sandy or clay, and encourages earthworms and soil microorganisms. It’s not a fertilizer per se, but it provides some nutrients. Rake 1/4 to 1 inch into your lawn once or twice a year.
  • Feed the soil, not just your plants. Choose a slow-release organic fertilizer—for example, an alfalfa-based fertilizer. As a general rule, you need to apply about three or four pounds of nitrogen per 1,000 square feet of lawn per year. To avoid overfertilizing, take into account the nitrogen in any grass clippings you leave on the lawn, as well as the nitrogen content of corn-gluten meal if you use it. Apply fertilizer spring and fall as needed.
  • Leave clippings on the lawn. It’s a cheap, easy way to add organic matter and nutrients to the soil. Clippings can provide half your lawn’s nitrogen needs—almost two pounds of nitrogen per 1,000 square feet of soil each year. It’s a myth that clippings lead to thatch; a soil with an active population of microorganisms breaks down clippings quickly, as long as you don’t mow more than one-third of height off the grass at a time. A mulching mower—or a mulching blade for your old mower—chops up the leaves into smaller pieces, which helps them break down more quickly. But it’s OK just to remove the grass catcher from your regular mower.
  • To fertilize and discourage weeds at the same time, apply corn-gluten meal if you wish. Corn-gluten meal doesn’t kill established plants, but it helps prevent crabgrass, dandelions, and other broadleaf weeds from germinating successfully. It also contains 9 percent nitrogen. The first year, spread 20 pounds per 1,000 square feet on your lawn in the early spring and the early fall. Water it in lightly, then let the soil dry out for a few days. At this application rate, you’re providing almost another two pounds of nitrogen to your lawn twice a year. You can reduce the amount you apply as the number of weeds decreases. It’s considered 60 to 90 percent effective, and possibly 90 percent after the first year. “By the fourth year, weed control should be very good,” according to a University of Minnesota Extension Service publication. An issue to consider: Much of the commercial corn in the United States is from GMO, or genetically modified, seed.
  • Set your mower blade high. Although different varieties of grass have different preferences, a general rule of thumb is to mow to three inches. This keeps the grass long enough to shade out many weeds. And leaving the grass plenty of leaf allows it to make itself plenty of food—good for plant health and strong roots. Don’t cut off more than a third of the grass height at one mowing; it stresses the grass. Be sure to sharpen mower blades regularly so you don’t shred the grass; ragged edges are a great place for disease to take hold.
  • Water an established lawn deeply and infrequently. This encourages grass roots to grow deep into the soil; there, they can still enjoy a drink between waterings as weed seedlings on the surface dry up. Water when the lawn’s color dulls and footprints stay in the grass for longer than a few seconds. Set a cup in the sprinkler zone to make sure you water an inch each time; it takes about an inch of water to penetrate deeply enough into the root zone.
  • Reseed. When you pull (or kill) a weed, you create a bare spot where more weeds can easily germinate. To beat weeds to the punch, reseed right away with grass. If you aerate, apply compost mixed with grass seed afterward. Seed with a variety of grass that matches in appearance the variety you already have.
  • Monitor for pests and pathogens. But if your lawn develops an infestation or a disease, don’t panic. First, identify the culprit and try to determine the underlying cause—too much water or fertilizer, say, or perhaps too little. If adjusting your horticultural practices isn’t enough, natural remedies are available. For example, you can control grubs with either milky spore (a bacterial disease) or nematodes (parasitic worms). Keep in mind that organic insecticides such as pyrethrin are still toxic; use them as a last resort, if at all.
  • Re-examine your attitudes toward weeds. “A lawn with 15 percent weeds can look practically weed-free to the average observer,” according to the Environmental Protection Agency. And a scattering of broadleaf weeds such as dandelions can actually be healthy for a lawn. Many have thick taproots that bring up nutrients from down deep; when the weeds die and break down, they release those nutrients into the top layer of soil, where grass roots can take them up. Some weeds also provide habitat for beneficial insects.

Taking It One Step Further

  • Test your soil. Overfertilizing can harm a lawn as much as a nutrient deficiency can. Consider having the soil tested for pH, percent organic matter, and nutrient content, including nitrogen, phosphorus, and potassium (N, P, and K) at a minimum, but preferably other macronutrients and micronutrients as well. Professional soil testing tends to be more accurate than home test kits; try the local extension office, or look for a lab that recommends organic fertilizers.
  • Adjust pH if needed. Grass does best at a pH of about 6.5 to 7.0, whereas dandelions tend to like it a bit more acidic. Adjusting pH if necessary can give grass the edge. Add lime to raise the pH or sulfur to lower it. Do this carefully, and only in conjunction with a soil test.

New Grass

  • If you’re putting in a new lawn, choose the right grass. Select a hardy variety or mix suited to local conditions. Grasses vary in their temperature and moisture preferences and in how well they withstand foot traffic and resist disease. If you want to start with sod, keep in mind that it’s rarely organically grown.