Roots and Shoots: How to Kill a Lawn

Preparing a yard with cardboard and wood chips for planting meadow-style Photo by P. Doan

Preparing a yard with cardboard and wood chips for planting meadow-style (Photo by P. Doan)

Our yards are not good for the planet. Loss of habitat compounds problems for wildlife and insects because lawns don’t offer ecological benefits. The way we maintain lawns with gas-powered equipment contributes to global warming through the release of carbon emissions. 

The synthetic fertilizers we use to make lawns green run off into waterways and the nitrogen creates harmful algae blooms. The herbicides and pesticides we use to maintain monocultures of turf grass poison everything in their path, including beneficial insects, pollinators and native plants. The water we use on landscapes sucks up 9 billion gallons a day from groundwater and reservoirs, according to the Environmental Protection Agency. 

So if you’re ready, spring is a good time to get rid of grass. Every method, from herbicides to sod removal to smothering, has its advantages and disadvantages.

Dan Jaffe Wilder, director of applied ecology at the Norcross Wildlife Foundation in Massachusetts, is an admitted lawn killer. (Large numbers of people making small changes makes a big impact, he says.) His preferred method is smothering. This involves using organic materials to cover the area to block photosynthesis. 

Start by cutting the grass as short as possible with a mower or string trimmer. Then cover it with cardboard or newspaper and layer compost and wood chips on top to create a planting medium. 

There are some details that are important to consider based on your site conditions, timing during the season and what you plan to grow in place of lawn. Soil is key to healthy plants and they have different needs. A vegetable garden requires more organic matter and nutrients than a native plant flowerbed, for example. 

Wilder uses the example of replacing a patch of lawn with native grasses such as little bluestem (Schizachyrium scoparium). This plant prefers thin, less-rich soils and wouldn’t grow well with the additional organic matter and nutrients from compost and wood chips. Wilder uses a topsoil and sand mix on the cardboard to establish little bluestem.

For an eco-lawn seed mix like the ones available from High Country Gardens, Wildflower Farms, Prairie Nursery and other online retailers, Wilder cautions that it is best to follow the grower’s instructions. They have trialed and developed the seed and know what works. 

Wood chips alone in a 12- to 18-inch thick layer can kill vegetation and in normal conditions will decompose over a few months for planting. Pull the chips back to put the plant into the soil. 

Here are some other methods, and their drawbacks.

Sod removal
It’s a lot of hard work and, when the living grass is cut out, it takes a layer of topsoil with it. A 3- to 5-inch section of soil has a lot of nutrients and microorganisms that plants need. It also exposes a seedbed of weeds that will start growing immediately. You’ll need a second step of weed control before planting anything new. 

Synthetic, broad-spectrum herbicides will get the job done with one or two applications. Wilder notes, however, that “we simply don’t know a lot about the effects or understand how it breaks down in the soil.” 

Organic herbicides such as horticultural-grade vinegar or clove oil can be toxic to the person applying them and should be handled with care, training and protective equipment. 

In regions with longer seasons of hot days and higher temperatures, clear plastic can be fastened to the ground to overheat the grass. But Wilder and another horticulturist who specializes in turf grass told me it won’t be effective in the Hudson Valley. 

Wilder mentioned a plant that I wasn’t familiar with, common selfheal (Prunella vulgaris), a low-growing member of the mint family with purple flowers, edible leaves and medicinal properties that can be encouraged or planted in a lawn alternative. He also likes wild strawberry, sedge and clove. All have big appeal for bees.

2 thoughts on “Roots and Shoots: How to Kill a Lawn

    • I recommend talking to an arborist or tree company and getting a load of chipped wood that is straight from the source without dyes or other treatments. Many local companies will sell wood chips or even do a drop-off for free. I would avoid using anything sold as mulch; it’s usually bark, treated or dyed, and won’t decompose well and add nutrients to the soil.

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