The Other Side of Greener Grass

Note: I originally published this in 2002 on kuro5hin.org

---

I don't know if this is true everywhere, but many US homeowners are really obsessed with their lawns. I guess growing grass around your house is better than pouring concrete. But considering the amount of water, pesticides and chemicals poured on lawns annually, maybe there's a down side... unless you go organic.

Sometimes growing things organically can be more difficult and more expensive, but in the case of your yard, just the opposite is true: For the most part, it's both easier and cheaper.

You may think reading about lawn care is about as interesting as watching grass grow, but come with me on a short (barefoot) stroll through the geeky side of organic turf maintenance....

---

Most people take one of three approaches when it comes to their yard. Approach #1 is to pay a lawn care service to spray (or spread) a variety of fertilizers, pre- and post-emergent weed killers, grub control and other chemicals on your grass, up to six times per year. Approach #2 is to buy your own fertilizers and lawn treatments and spread them yourself. Approach #3 is to just mow your grass and/or weeds, and not really worry about it.

There is a fourth choice: Organic lawn care. Don't let the word "organic" scare you away. If you're currently using approach #1, organic should save you money. If you're using approach #2, organic should save you time, and possibly money too. If you're using approach #3, this might be slightly more work, but it'll improve your lawn and reduce your weed population.

So how do you do it? Any of the following adjustments to your routine should improve your lawn. The more of these methods you adopt, the more success you'll have.

Set mower to cut your grass high (3 inches is good).

• Taller grass creates more shade for roots, less sun for weeds.
• High mowing keeps more of the blade intact. You don't want to remove more than 1/3 of the blade when cutting.
• Grass cut short will expend all its energy into producing more blade so it can photosynthesize enough to keep it going. Grass cut long will put its energy into creating more roots (including the extra energy it gets from having more leaf surface to photosynthesize with).
• Cutting your grass short won't necessarily mean more time between cutting. Grass cut short will often grow faster because it doesn't have enough leaf surface to meet its needs.

Go easy on the fertilizer.

• You really don't want new growth in the middle of summer. For one thing, lots of new growth during heat stress or drought conditions will do more harm than good. For another thing, who wants to cut the grass in the sweltering heat? And if it's hot enough for your grass to go dormant, then applying fertilizer is only going to benefit the weeds.
• One application of fertilizer in spring and another in fall should be plenty for most lawns. According to one source, "the average lawn uses 10 times the amount of chemicals per year than an acre of farmland." That seems excessive for something that is mostly cosmetic.
• When looking at fertilizer, higher values for N-P-K are not always better, just as taking three vitamin tablets at a time isn't necessarily better than one.
• Slow-release nitrogen fertilizers (such as cottonseed meal or blood meal) will feed your grass over a longer period, instead of giving it a big jolt of nutrients all at once.

Don't bag your grass. Use a mulching mower.

• Leaving your clippings on the lawn is a great way to improve your soil over time. It will add organic matter and nutrients back into your soil, and provide a little extra shade. This will help the soil maintain a more even temperature, retain moisture, and make it harder for weeds to grow.
• Dull lawnmower blades are hard on your grass, so keep those blades sharpened. It doesn't cost much to have your blades sharpened once every year or two.
• If you want to bag your grass when company's coming over, or if you need some extra material for a compost pile, bagging isn't harmful. You just don't get the benefits of leaving the clippings on.

Or better yet, consider a reel (push) mower.

• Reel mowers make a cleaner cut. Instead of tearing the tops of the blades, it's more akin to cutting them with scissors.
• Reel mowers require no gasoline, no oil, no spark plugs, very little maintenance, and no struggling with a temperamental motor on a cool day. Just shake any loose grass off, spray the blades with WD-40 (or similar) after each use, and get the blades sharpened every year or two.
• Modern reel mowers are wider, lighter and easier to push than older models. It still might require a little more push than a self-propelled gas mower, but not by a lot (especially if you've got it set to cut high).
• Reel mowers are very quiet, so if you want to cut your grass at 8:00 am or 9:00 pm when it's cooler, you won't be annoying your neighbors.
• Reel mowers do have a couple strikes against them: They're still not as wide as most gas mowers, so you'll have to make more passes. Some don't do well on uneven ground. And they don't do well if you let your grass get too long. But hey, if you're walking more, pushing slightly harder, and cutting regularly, you and your grass will both be healthier. Maybe you can even cancel that expensive health club membership.

If you water, water intelligently.

• Many grasses go dormant during drought or heat stress conditions. This doesn't mean your grass is dead. As with fertilizing, watering your lawn when it is very hot means (a) you have to mow more, and (b) you're creating tender new growth that can may be more affected by heat stress.
• Less frequent watering will cause your lawn's roots to grow deeper. This will help keep your grass going during dry periods, while the weeds are drying up and dying.
• When you do water, water deeply (the equivalent of one inch of rain). If the water is running off, stop, let it soak in, and water more later. Shallow watering encourages shallow roots, which dry out quicker, or thatch (a layer of above-ground runners).
• Water early in the morning. Watering later in the day can (a) promote fungus if the water doesn't soak in or evaporate before dark, or (b) cause water droplets to act as little magnifying glasses when the sun's rays are at their peak intensity. In addition, the water is more likely to be absorbed by the grass if you water when the air temperature is increasing. As the temperature rises, a plant will begin to transpire water through its leaves. When transpiration occurs, water is drawn upward through the plant. This in turn, pulls water from the soil into the plant's roots.

Eliminate, or cut back on, grub killer, pesticides, and weed killer.

• Spreading weed killer over your entire lawn to kill a half dozen weeds is, well, overkill.
• Even "safe" chemicals may not be all that safe. According to once source, "2-4D is considered the safest herbicide. A quantity of 2-4D that would be about the same as a roll of life savers rubbed on the skin of four kindergarten children would kill two of them. This is not getting it in their mouth, but just rubbed on their skin."
• In addition to killing unwanted pests, you'll be killing, harming, or chasing away lots of beneficial critters as well. Earthworms, lacewings, ladybugs, praying mantids, and micro-organisms like beneficial nematodes can all be harmed by overuse of poisons and pesticides.
• Birds may also be affected by consuming the pesticides, either from eating the bugs, worms, etc. or from drinking runoff water. They may also be affected by direct contact with treated grass or foliage. One estimate states that "over 60 million birds die as a result of exposure to chemical pesticides and fertilizers".
• Instead of spreading several pounds of weed killer, just bend down and pull weeds out by the roots as you mow and toss them in front of the mower to be chopped into mulch. For really persistent weeds, spot spray them with weed killer. If you're keeping your grass healthier, your weed population should stay down anyway.

Get yourself some nematodes.

• Instead of chemical grub control, add some beneficial nematodes to your soil. Nematodes are microscopic worms that infect and kill many garden pests. They are readily available from many sources.
• Pests controlled by beneficial nematodes include: Japanese beetles, June bugs, weevils, midge flies, rootworms, cutworms, billbugs, craneflies and fleas. They are typically affected in the larval stage. Few beneficial insects and organisms are affected by these nematodes.
• One nematode treatment is fairly inexpensive (less than $40) and can last several years.
• Nematodes can be applied either in dry or liquid form. Apply in spring or fall.
• Not all nematodes are beneficial. Some are actually harmful. I don't imagine you're going to go out and buy the harmful ones though...

Aerate your soil occasionally.

• Aeration will help your soil be less compacted, which benefits your lawn's roots as well as the beneficial micro-organisms that keep your lawn healthy. This is needed no more than once per year.
• Core aeration is preferred because it actually removes small cylindars of soil and deposits them on top of the lawn to break down. Other types of aeration create air pockets by compacting the soil even further in some places.
• If you core aerate, leave the plugs of soil on your lawn. You might think they look strange, but they'll break down in a week or so, and you'll be keeping those nutrients in your lawn. Besides, if you're mowing high, they won't be that noticable anyway.
• Core aeration will be less effective during drought conditions, so if you've had a dry summer, you might want to wait until after it rains a little before aerating.

Overseed occasionally.

• Spreading seed on top of your lawn in the fall will help make your grass thicker, thus crowding out more weeds.
• Overseeding with a mix of grass seed (for example, northern US lawns might use a mixture of fescue, bluegrass, and rye) can create a more biologically diverse turf, which makes it less susceptible to problems. If conditions arise that are tough on your bluegrass, and all you have is bluegrass, all your grass is at risk. If you have a mixture, one variety may thrive while another is suffering.

Topdress occasionally.

• Topdressing your lawn involves adding a light layer of extra soil or organic matter (like compost) to your lawn. The better your soil, the healthier your grass. The healthier your grass, the less room for weeds.
• Topdressing allows you to gradually improve your soil without the effort and expense of starting from scratch.

Learn a little about your weeds.

• Some people love the look of dandelions and let them grow freely in their yard. Then there are those people don't want to see a single weed anywhere on their property. Anything that's not grass must die. But before you rip out that attractive, lush little patch of clover, consider this: clover (white and pink in particular) can actually take nitrogen out of the air and put it into your soil. Grass loves nitrogen. Just something to think about.
• If your lawn is over-run by dandelions, try lowering the pH of your soil with garden sulfur (or similar). Dandelions like a higher pH level than grass. You might consider having the pH of your soil tested. Most states have County Extension Offices or university-sponsored office that will test your soil for free.

A few other assorted notes...

• If you're going to convert from a chemical lawn treatment program to an organic treatment program, your lawn may have problems in the short term. All those beneficial organisms may be absent, and your lawn will have been living on a steady diet of supplements. It's hard to get the natural machinery for a more self-sustaining lawn up and running instantly. Your lawn is, in a sense, "addicted" to chemical supplements because that's its only source of nutrients. There may be a period of "withdrawal" before you see the results of your organic lawn care efforts.
• If having the absolute greenest lawn on the block is a priority, you probably won't be able to accomplish this organically. But you can have a healthy lawn that won't drain hundreds of dollars in fertilizers, chemicals, pesticides and unnecessary watering from your wallet every year. If your self-esteem is really that closely tied to how green your lawn is, try going organic, and using the money you save for a little professional counseling...
• Here is an entertaining (if a bit over-simplified) perspective on lawn care.

References:
Organic Lawn Care for the Cheap and Lazy
Organic Lawn Care Guide
Organic Lawn Care Tips
Audubon Workshop