Organic Lawn Maintenance
Weeding, Watering and Mowing
By Bill Kohlhaase, Planet Natural
Your new organic lawn is up and growing. Or you’ve cut out using herbicides, pesticides and chemical fertilizers on your established lawn. Congratulations! Now what do you do to maintain your organic lawn in a way that’s best for it?
Not surprisingly, what you do to keep up your organic lawn is pretty much the same as you would with a traditional lawn. One difference? It may be less work to keep up your organic lawn. How is that possible? By using spring and fall applications of compost, by returning your grass clippings back to your lawn, by proper watering you will have a rich, thick cover of grass that will crowd out weeds and discourage pests. And you thought this would be difficult.
Like all types of gardening, the various facets of lawn maintenance are all inter-related. Taking care of one aspect, say using proper mowing height, rewards other aspects like weed control. Let’s start with fertilizing.
It’s well known that the best way to keep your lawn healthy and green is to provide it with healthy soil. Amending with compost contributes to the quality of your soil which, in turn, contributes to the health of your grass. Spring and fall applications of compost may be all your lawn needs to be healthy, especially if you’re returning grass clippings to your soil during the growing season with the “no-bag” mowing method, which will supply 25 to 50 % of your lawn’s nutrient needs. The healthier your lawn is, the more nutrients you’ll be returning to it when you mow.
Using compost to enrich your lawn’s soil is ideal for several reasons. Applications of compost encourage the growth of beneficial microbes that help fix nitrogen from the air while releasing a broad array of balanced nutrients already in the ground. It will enter your soil slowly providing a time-release effect. Adding organic material to your soil helps grass more efficiently utilize any other supplements you might add. Organic material makes soil more friable; more able to hold moisture and with plenty of space for the oxygen that plant roots and beneficial organisms need.
Obtaining enough compost to spread on your yard can be a problem. Nor is it easy to apply even the most finely screened compost with a traditional fertilizer spreader. But compost doesn’t have to be spread as carefully or evenly as a concentrated fertilizer would. Just throw shovelfuls around your yard and then rake to spread it. A good watering, though usually not needed during the wet months of spring, will help it work its way off any grass it may have covered.
There are several fine all-inclusive lawn fertilizers available to those who wish to supplement their compost and grass clipping applications. These products not only provide nitrogen and other nutrients in perfectly balanced formulas, they can also contain beneficial microbes and fungi to enliven the health of your soil and fight diseases. Using them in conjunction with compost helps guarantee that your lawn will be able to take full advantage of the nutrients it provides. Other organic fertilizers will help remedy specific nutrient needs revealed by soil testing. If your lawn is low in nitrogen, an application of blood meal (13-0-0) or cottonseed meal (5-2-1) will give your lawn a quick, though expensive, nitrogen boost. Using high nitrogen manures, especially chicken manure, may cause burning, especially if left to lie without rain or watering. In most cases, an application of well-balanced organic fertilizers, such as fish meal (9-4-1) or liquid lawn food (8-0-2), will be sufficient.
Traditionally, fertilizers are applied in the spring to help grass green up quickly. But the Ohio State University Extension Service cites research that recommends fertilizing be done once in late summer and again in the fall to encourage strong root growth. Good root growth in the fall encourages better top growth in the spring. Fall fertilization also contributes to better color late in the fall, earlier spring green-up, and fewer disease problems.
If you choose to use an organic fertilizer product, look for one certified by the Organic Materials Review Institute (OMRI) to insure its organic quality. Because the ingredients in organic fertilizers must break down before being taken up by your grass, they have much the same time-release effect as will compost. In fact, adding compost to your soil will help grass better utilize any fertilizer you might apply.
Organic fertilizers with naturally occurring iron will help green up lawns for that deep, rich color your neighbors will covet. Some will contain nitrogen-providing germination inhibitors like corn gluten (see below) that will keep weeds from getting a start in your lawn when applied in the spring. Which ever form of organic fertilizer you use, be sure to follow label directions carefully, especially as to application amounts. While most organic fertilizers won’t cause burning, you don’t want the expense of over-fertilizing or the possibility that excess fertilizer will run off and enter lakes, rivers and streams. And applying too much nitrogen to your lawn, despite the fact that it will make it “green up” almost immediately, weakens grass in the long run, making it more susceptible to pests and disease.
A properly trimmed lawn will encourage your grass to grow deeper roots, thus enabling it to draw nutrients and moisture from deeper in the soil and protecting it from drying out prematurely. Organic lawns will benefit (as will non-organic lawns) from being kept at a slightly taller height than traditional yard carpets; say 3 to 3-1/2 inches. Grass at this height will shade out weed starts. Taller grass will also allow for more photosynthesis-generating surface area, which means a greener lawn.
On the other hand, don’t let your grass grow too tall. Mowing tall grass results in “scalping,” broken and severely-cut grass ends which will make it more susceptible for disease. The rule of thumb is never to cut more than 1/3 of the total blade length. This may mean going back a few days after mowing after giving your grass time to recover, and cutting again to gain the desirable 3 to 3-1/2 inch height. Some grasses may be cut shorter than others. Cool season grasses including bent grass and rye grass may be trimmed to 2-1/2 inches (but you’ll be providing weeds easier access to sunlight). Warm climate grasses such as Bermuda grass grow more slowly and do not need as frequent cutting. But they should not be allowed to grow too tall as this requires more watering to sustain the color. Always consider local conditions before choosing a yard grass and before mowing.
Keeping mower blades sharp helps prevent the kind of shredding that gives disease an inroad into the plant. Sharpen those blades at least once a season, more if you’re hitting sticks, gravel or obstacles. Dry grass cuts more cleanly than wet. And cutting dry grass is easier on the mower. Don’t be tempted on those free Sunday mornings to get out early and mow before the dew has evaporated. Not only will you wake the neighbors, you’ll not give your lawn the clean trim it needs.
Reel mowers are becoming more and more popular. Not only are they noise and pollution free, they’re a good source of exercise. It’s especially important to keep reel mower blades sharp. It’s also easier to keep them sharp by avoiding obstacles or approaching uneven ground from the correct angle. No matter what kind of mower you use, take the time to cut swaths only half as wide as the mower itself. This means your grass is mowed twice, ensuring that the cuts are clean and even. Always use the ultimate caution when mowing lawns. This means using proper starting techniques and wearing proper clothing, shoes and, under certain conditions, eye protection. More on lawn mower safety here (PDF).
Watering may be the most difficult part of natural lawn care. Why? Because, unless you live in extremely dry conditions (in which case you probably should be planting native plants and grasses), you probably shouldn’t do it. This requires discipline and a willingness to tolerate a lawn that in late summer might not look as inviting as your neighbor’s heavily-watered, artificially-maintained patch of green. Grass naturally goes dormant, turning brown when the summer is at its warmest and rain is scarce. Dormancy is part of its life cycle. Frequent watering during this dormant period makes your grass weak and dependent. Experts believe that letting grass go dormant during the dry season makes it more likely to survive harsh winters intact and in healthier condition. And it makes lawns more resistant to disease.
Most of us want our yards green even in the dog days of summer. This will mean inflating your water bill and, in some areas of the U.S., tapping a shrinking resource for the sake of vanity. If you must water, do it intelligently. Deep infrequent watering coupled with proper mowing will increase the hardiness of your grass, giving you deeper, nutrient-slurping roots and denser cover for shading out weeds. Frequent, shallow watering is wasteful. It makes you grass dependent, its short roots unable to pull moisture from the soil when it needs it.
There’s all kinds of advice out there for the amount of watering lawns need (see Save Water On Your Lawn). It ranges from those saying to water lawns one-inch a week (measure this amount by putting out an empty tuna can in your yard and when it’s full, turn your sprinkler off) or waiting between waterings until the tops of the blades start to curl but before they turn brown. Accepted advice suggests watering in early morning to prevent rapid evaporation and not to water in the evening (a popular time in my last neighborhood) because over-night moisture will encourage insects and disease.
How much you water — and when — will depend on your soil and climate conditions. Pay attention to your lawn, water only when necessary and then do it deeply. Your goal is to encourage deep root growth. This results in a lawn that is greener, thicker and less likely to be assaulted by weeds and insects. In early season, don’t water until spring rains become infrequent. During the fall, when your grass has come out of dormancy and begins to put on growth to survive the coming winter, water only during warm and dry, Indian summer periods. And finally, don’t be afraid not to water at all. If it’s been encouraged to grow properly, it’s tough enough to take it.
As we’ve noted before, the best defense against weeds in your lawn is to have a thick rich cover of grass. Organic gardeners will tolerate a few weeds in their yard; they see them as a tradeoff for knowing that they aren’t contaminating the environment with herbicide run-off or threatening the health of their children, pets, birds and other creatures by spreading poison. Organic growers are much more likely to tolerate clover in their lawns than the up-tight neighbor who kills off every broad leaf plant in his yard by spraying. But if weeds are a problem, say before your lawn has reached the stage where it protects itself, there are things you can do without compromising your organic principles.
Corn gluten discourages seed germination and can be effective in preventing weeds from growing in soil that is ready to be set with sod. In an established lawn, corn gluten meal can prevent germination of weed seeds if the timing of its application coincides with germination, generally early spring. Timing is important. Corn gluten doesn’t discriminate. If you’re reseeding any part of you lawn, it will also discourage germination of your grass seed. Do not spread it on bare spot or other places you intend to seed. Once weeds are established, corn gluten will not kill them. And because you use so much of it — 20 lbs per 1,000 square feet — its cost can be prohibitive (that price may come down with the phasing out of ethanol subsidies). Corn gluten has another advantage: It’s a great nitrogen fertilizer (9-0-0) that can take up to four months to be released. You can’t go wrong spreading corn gluten in the early season, unless the weed seeds have already started germinating. Then it will nourish them, too.
The number of organic and natural weed-control products seems to increase every year. Many of these use salts, soaps and plant oil (including citrus oils) to attack plant cells or dry up leaf-moisture. Be sure any natural herbicide you choose to use in your lawn is safe for grass. Many are indiscriminate and will kill grass as well as broad-leafed plants. Fitting a plastic tube cut from a piece of pipe or a thin plastic bottle over the nozzle of your herbicide sprayer will help focus it on your intended target.
Household vinegar, sprayed directly on weeds, is effective in killing broad-leaf, shallowly rooted weeds but only above ground. It doesn’t harm the root, so try to catch weeds early if using vinegar. Then pull. Horticultural vinegar is designed specifically for weed killing — it contains 20% acetic acid as opposed to 5% in household vinegars — and does a more effective job. Manufactures suggest 20% vinegar will kill dandelions root and all if you inject the solution into the plants roots using a syringe and a sturdy, say 400 cc or larger, needle of the sort used for animal injections. Again, pulling the intruder once its leaves have failed (not always an easy thing to do) will help guarantee against its return.
In fact, pulling or digging is our favorite organic method of weed control. While impractical for some invasive, spreading-root weeds like chamomile and spreading violets, and more established, late-season weeds including dandelions and thistles, it can be highly effective (though tedious) if done efficiently. An old dandelion fork can make sure you get most if not all of the root. There’s a certain aesthetic pleasure sitting in your organic lawn digging out weeds. You’ll get to know your yard inch by inch. And if you have composted and otherwise nourished your grass to grow thickly, they’ll be few weeds to pull.
The best way to avoid problems from pests in your lawn, according to the Agricultural and Natural Resources Department at the University of California, is to keep a healthy lawn. Insects are opportunists. They usually attack weakness in lawns; areas of thatch or browning. Avoiding these problems is the best way to prevent problems with grubs, moths and cinch bugs. Improving your soil with compost ensures a healthy population of microbes that help keeps pests from reproducing.
There are many organic pest control products on the market that are derived from plant oils that have repelling or killing properties. If you see brown or thin spots in your lawn that aren’t due to too little water or poor soil conditions, it’s time to inspect closely, maybe turn a spade full of soil over to look for grubs or comb the grass for beetles. Don’t be alarmed when your grass goes naturally dormant. This is usually a time when it’s least attractive to insects as well.
Don’t let leaves to build up on you lawn in the fall. Rake them up for compost or better, run a mower over them to so they’ll integrate into your soil. Leaves left whole on a lawn, or a covering of mowed leaves that bends and buries grasses, can be harmful, suffocating the grass and making an opportunity for disease. Mow your lawn approximately 1/2 inch shorter at the end of the season. This will help it avoid snow pack that will bend or damage the blades and provide opportunity for disease (see Preventing, Curing Snow Mold).
Lastly, enjoy caring for your organic lawn, knowing that you’re doing the right thing for your family and the environment. You’ll be setting a great example to your neighbors, using less water, avoiding chemical fertilizers and herbicides. When they see the results, maybe, just maybe, they’ll want to make their lawn organic, too.