How to Transition Your Lawn Off Chemical Fertilizers and Weed Killers

You’ve made the decision to lose the lawn chemicals and practice organic lawn care. Congratulations! That decision alone gets you halfway there.

The first season of organic lawn care is the trickiest because your grass has been on a steady diet of synthetic chemicals for years or maybe decades, which has caused significant damage to your soil. Years of synthetic fertilizers, herbicides and pesticides being applied to your lawn have most likely left the soil in terrible shape even if your lawn appears green and lush. The grass keeps its color because of the enormous amount of water-soluble nitrogen in chemical fertilizers. If you’ve been on the standard feed-twice-a-year program, you’ve fertilized the lawn much more than it needed by magnitudes.

“$5.25 billion is spent on fossil-fuel-derived fertilizer for U.S. lawns. The majority of this fertilizer is wasted because of improper timing or dosage and becomes a source of pollution to surface or ground water. Most of this expense and pollution could be eliminated by proper timing, proper dosage, or intelligent use of compost and other organic fertilizers.”

Purdue University’s Beneficial Lawn Care And Chemical Management website.

Steps to transition your lawn off chemicals.

Feed the soil.

The central principle of organic lawn care is feed the soil. When the soil is in balance and abundantly healthy, it supplies plants with what they need and creates a healthy, robust ecosystem. Once you get comfortable with this “working with” point of view, instead of the chemical “doing to” view, organic lawn care makes a lot more sense.

Rake up thatch.

Thatch is that layer of dead grass, roots and rhizomes which collect at the soil’s surface. Rake it up and put it in a compost pile. Synthetic fertilizers acidify the soil and chase away the bacteria and other organisms that break thatch down and incorporate it into the soil. When thatch becomes too thick, it resists the absorption of rainwater, much of which runs off. After 2 seasons of organic lawn care, you’ll have little to no thatch, as the soil food web will continuously break it down.

Aerate your lawn.

Aerators pull two-inch plugs from your lawn, which are left in place to decompose over one or two weeks. The small holes they leave behind provide a path for water and nutrients to feed the grass’ roots. If you have a small lawn, a manual step-on aerator will do the trick. If your property is more substantial, rent a mechanical aerator from a local equipment store.

Examining the plugs can be a great education about the condition of your soil. The first time I did this, shortly after buying my home, my lawn problem became obvious. The plug was almost entirely hard packed clay, with thick thatch on top and only a very thin layer of dark top soil where the grass roots lived. Ultimately, that dark layer of top soil should be at least one inch deep, as that’s where nutrients are most available and where beneficial microbes do their best work. The top soil suffers most under the stress of chemical applications.

Add organic material to your lawn.

After aerating, spread composted manure or finished compost over the lawn, as you would any bagged fertilizer. Years of lathering your lawn in chemicals have killed or significantly reduced the earthworms, beneficial insects, fungi and bacteria that would normally sustain the lawn – the manure and compost invites them back. Bags of composted manure and yard waste compost are available at any garden center, and are relatively inexpensive. The composted manure – animal droppings which have been composted to remove any pathogens – has no foul smell.

For the first 2 seasons, spread organic fertilizer. The nitrogen content is not as high as in the synthetic forms and does not break down as quickly – it’s slow release, so it will take a little longer to see the “greening up” you’re used to. But the organic fertilizer and composted manure will work together to get your lawn and soil back into shape, thus creating a healthier and more sustainable lawn. After two seasons, you’ll no longer need the organic fertilizer, as your grass will be less dependent on chemicals, but adding compost yearly keeps the soil healthy.

Buy a mulching blade for your lawnmower.

If you’ve been bagging your lawn clippings, or cutting with an old mower that leaves piles of grass clippings on the lawn, buy a new mower with a mulching blade. Mulching blades pulverize the grass as it cuts, and the fine clippings lay at the soil surface, where they quickly break down. This is all the food your grass needs. But you’ll need the compost and organic fertilizer mentioned above until the decomposition cycle and the soil food web is in full swing. Also, only cut your lawn when it’s at three inches.

Re-seed your lawn.

You’ll still be using the same methods of seeding, so do what’s appropriate here. Be wise about what kind of grass seed you use: it should be the appropriate grass for the climate in your area.

Treat lawn weeds organically

If you have weed problems, the best pre-emergent treatment is corn gluten meal. CGM inhibits root formation at the time of germination, and is a by-product of corn milling. As it breaks down it provides more nitrogen to your lawn, giving it a boost mid-season. But don’t seed your lawn within 6 weeks after using CGM, as it inhibits the roots from any seed. Corn Gluten Meal won’t provide instantaneous results like chemicals do, but after three seasons or so, you should be able to knock out about 85% of your weeds.

Clover is not a weed. It is in fact very important for your lawn’s health, as it fixes nitrogen in the soil and gives many nutrients back to it. It’s also one of the few early spring plants from which bees can collect nectar.

After two seasons of organic lawn care, I assure you that it will look just as good as it did when chemically dependent, but it won’t contribute to fertilizer runoff, soil depletion, burning your cat’s or dog’s paws, skin irritations, breathing difficulties, or any number of nasty things that chemical applications can produce. You also won’t have to stick little yellow flags in your lawn warning people to not walk on it. Unless you want to.