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Is Your Lawn a Chemical Dump?

lawn treatment chemicals

Since the late 1940s, chemical companies have encouraged Americans to “weed and feed” their lawns every spring and fall. We bought it hook, line, and sinker, believing that more chemicals equaled a greener, healthier lawn.

As a result of this indiscriminate use of fertilizers and pesticides, we have an overabundance of nitrogen and phosphorous in our waterways, and soil that can’t support the grass growing in it without the help of more chemicals. Many American lawns have basically become a chemical dump.

Your lawn doesn’t need synthetic fertilizers if they’re fed naturally.

Grasses are plants like any other. In the wild, where grasses have thrived for millennia, they’re supported by decomposing organic matter at the soil line, that eventually becomes humus, the nutrient-dense material which supports all plant life. The decomposition cycle is dependent on the many microorganisms and other creatures that live at or just below the soil line. This is called the soil food web.

This natural cycle can be easily replicated in your suburban landscape, because there’s no shortage of organic material. In fact, cut grass itself is the best source. A lawnmower with a mulching blade cuts and pulverizes grass clippings into tiny particles which fall to the soil line. There, the soil food web breaks them down into their component nutrients: 4 percent nitrogen, 2 percent potassium and 1 percent phosphorous, according the Missouri University Extension. These same nutrients are the foundation of bagged lawn fertilizer, but in much larger quantities (shown as NPK percentages on the ingredients label). 

Shredded grass clippings are the perfect lawn food, as they break down slowly all season, providing a consistent source of nutrients. The mulched grass clippings also insulate the soil, increasing water retention and regulating soil temperature. This insulation slows water evaporation and helps roots grow deeper.

If I fertilize my lawn more often will it grow greener?

The short answer is “no”, and overfeeding creates other problems.

When too much synthetic nitrogen is applied, or applied at the wrong time of year relative to your type of grass, the grass grows too quickly, resulting in lots of leaf growth and little root development. This makes the lawn very susceptible to drought and pests in the summer. Deep roots are the key to a healthy lawn, not top growth. A lawn with shallow roots gives up the ghost quickly during a drought or heat extremes. Additionally, plants will use only the nutrients they need at any given time and the rest runs off into local waterways.

Related Post:  How to Transition Your Lawn Off Chemical Fertilizers and Weed Killers

When to feed your lawn

If you live in the mid-Atlantic or northern U.S

In areas with cool climates, you have cool-season grasses in your lawn – or at least you should. Examples of cool-season grasses are Fescue, Ryegrass, Kentucky Bluegrass, Timothy, or Canary Grass. Cool-season lawns should only be seeded in the fall. If seeded in spring, sufficient time doesn’t exist for the perennial seeds in the mix to germinate and establish before summer heat sets in. The grass that pops up in the first 2 weeks are annual varieties that will die in the summer heat. They’re included in the seed mix to protect and shade the soil while the perennial seeds take more than 4 weeks to germinate.

Cool-season grasses should be fertilized with a slow-release nitrogen fertilizer in September and October only. Slow-release fertilizers like organic formulations stimulate slow and even top growth. This will encourage root growth, a thicker turf, and an early spring green-up the following year without causing too much top growth. When applied in the spring, high rates of nitrogen stimulate too much leaf growth and may predispose the lawn to greater summer damage. During the summer, cool-season grasses go dormant from the heat, so roots can’t take up any fertilization – all that you apply will runoff into local waterways.

If you live in the southern U.S.

In the South, you have warm-season grasses in your lawn, like Zoysia, Bermudagrass, St. Augustine Grass, and Carpetgrass. Warm-season grasses slowly green-up in spring, grow like mad in the summer, and enter dormancy at the first sign of frost. Feeding is the opposite of cool-season grasses: fertilize when the grass begins its active growth in May and June. Again, for slow and even growth, use a fertilizer containing a slow-release nitrogen source. Warm-season grasses should not be fertilized in the fall.

Far and away, the best organic product to fertilize your lawn (besides mulched grass clippings), is Corn Gluten Meal. It’s a by-product of corn milling and slowly releases nitrogen throughout the season. As an added benefit, Corn Gluten Meal acts as a weed suppressant by interfering with the germination of crabgrass seeds and other unwelcome weed seeds in your lawn.

 Buy on Amazon: Lawn Mowers with Mulching Blades 

The truth about lawn thatch

Contrary to popular belief, mulched grass clippings do not create thatch – the overuse of chemicals does. When a lawn is bathed in chemicals, the pH of the soil drops, and it develops a high salt content. Bacteria and other organisms which make up the soil food web can’t survive the acidic, salty soil, and either die off or retreat below to where the soil pH is normal. In a healthy organic lawn, these organisms live at the soil line and break down whatever organic matter and grass parts are present, including grass clippings. When these organisms retreat, that decomposition doesn’t happen, and thatch forms.

Related Post:  How to Combat Erosion in Your Yard

A few more lawn tips

When you mow, remember that the best mowing height for most grasses is 2.5 – 3 inches. This height allows the grasses to develop deep, strong roots, and the foliage grows tall enough to shade soil in extreme heat and drought. It’s also the right height for the mower blade to efficiently mulch the clippings.

Just because a lawn fertilizer is from an organic source, that doesn’t mean it’s safe to apply indiscriminately. Only apply organic fertilizer at the proper time of year and in the proper quantity per square foot.

The bottom line is a feeding of corn gluten meal and mulched grass clippings are sufficient to nourish any lawn. But the honest truth is, your lawn doesn’t really need any fertilizer. I haven’t used it in years, organic or otherwise, and you’d be hard pressed to tell the difference.

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