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Your lawn has a microbiome too. Here’s how to feed it
Your lawn has a microbiome too. Here’s how to feed it
There’s a secret balance going on under the grass. Learn how it works and the benefits that await
By: Hallie Levine
“Microbiome” has become a big buzzword lately. Most of the time, when the term is used, it refers to the trillions of bacteria, fungi, viruses and other microorganisms that live inside your gut. They digest your food and help keep your immune system humming.
But you can find another type of microbiome right outside your kitchen window. The soil in your garden has its own collection of critters that helps to keep it healthy and thriving, says Daisy D’Angelo, PhD, a horticultural scientist and researcher at ScottsMiracle-Gro. “Just like the human gut, it needs to have the right balance of microbial diversity to help it thrive,” she explains.
Your soil’s microbiome: Helping your garden grow
Here’s a fascinating fact: a single gram of soil contains more microorganisms than the entire human population, according to a 2026 study published in the journal Nature. These include bacteria and fungi as well as other, one-celled organisms like archaea, protists, and microalgae. “They all work together to help provide a healthy ratio of carbon and nitrogen that promotes overall soil health,” says D’Angelo. She adds that if this ratio is off at all, it can cause soil problems and imbalances that impact the quality of your lawn and garden, including the plants it produces.
A well-balanced soil microbiome doesn’t just benefit your lawn’s health. Research suggests it may improve your own wellness, too. One 2022 study published in the journal Scientific Reports compared the human and soil microbiota of gardening families to non-gardening ones. The gardeners, especially the ones with the most flourishing gardens, tended to have healthier gut microbiomes than the control group. Want to join their ranks? These moves could help.
4 ways to keep your soil microbiome healthy
When it keeps to our own gut microbiomes, medical experts usually recommend a diet rich in fruits, veggies, whole grains, and fermented foods, as well as regular exercise and hydration. “In many ways, the same can be said for your soil microbiome,” says D’Angelo. Here’s what soil experts recommend:
1. Feed your soil the right nutrients
When you garden, your focus is probably on providing plants with TLC. But it can be smart to shift your mindset slightly, from feeding plants to feeding the soil, says D’Angelo.
One of the best ways to do that is with organic matter, which is made up of living, dead, or decaying plants or animals. “These are teeming with microorganisms,” says D’Angelo. “Organic matter is carbon- and nutrient-rich, and the primary food source of the whole soil ecosystem.” It will help your soil retain moisture and nutrients and attract more “good” microorganisms to the soil.
You can buy organic matter online at websites like ScottsMiracleGro.com or at a local garden center. You’ll want to mix two to four inches to the top six to nine inches of your soil. You can apply it to your flower and veggie beds, tree beds, and even on the top of the soil in your lawn.
2. Try not to till your garden too much
Research suggests that you should avoid tilling your garden, as it disrupts soil and makes it harder for air and water to penetrate through. It also can disrupt the microorganisms that live in the top couple of inches, WHICH are key for soil health. “These produce nutrients that essentially bind soil particles together, to keep it open,” explains D’Angelo.
When you clean up your garden at the end of the summer, cut off the tops of your plants, but leave roots in the soil. This way, the roots can decompose and provide nutrition for hungry microorganisms, enhancing the soil microbiome.
3. Mulch it up
Mulch protects your soil’s microbiome since it helps to hold in moisture, moderates temperature, and soaks up rainwater so it doesn’t drench soil, notes D’Angelo. When it decomposes, it adds even more organic matter.
Many experts recommend that you apply your layer of organic matter in the fall, and mulch garden and tree beds in mid-spring. When you apply mulch around a shrub or tree, keep it three to five inches away from its base. Avoid non-organic mulches like stone, gravel or landscape fabric, since they can harm beneficial microorganisms that live on the top of soil.
4. Get your soil tested
When your healthcare provider is concerned about your gut microbiome, they often have you provide — yup — a stool sample to look for markers of inflammation. When it comes to your soil’s microbiome, a soil test (also a kind of sampling process) can check levels of macronutrients. It can gauge the amount of phosphorus, potassium, calcium, and magnesium, as well as nitrogen, your soil’s pH levels, and the level of organic material in your soil, says D’Angelo. (Your call if you want to try this tactic before or after the moves mentioned above.)
You can purchase a test kit online, at most garden centers, or contact your local cooperative extension office. Most soil test reports provide recommendations to optimize your soil, too.
Whether you try one or all of these moves, your soil microbiome is likely to thank you — with a yard that’s healthier and that makes you happier to spend time in it.
About the writer
Hallie Levine is an award-winning health journalist for such publications such as Time, Parents, and Good Housekeeping. She lives in Fairfield, Connecticut with her three kids and her dog, Wiggins.