Healthy Soil

Nurturing the life support system for our planet.
Learn more about healthy soil.
Cut away dirt viewed to show grass roots from the side

Billions of microbes live in every scoop of soil on Earth. Here are five practical tips to foster aerobic soil biology and plant health.  

Tip #1: Cover the Soil In Green

Utilize cover crops on farms and living mulches to keep the ground green. Mulches can be used as short-term measures to cover the soil between garden plantings or annual seedings to help avoid soil compaction caused primarily by rain hitting bare ground.

Compacted soil eliminates airflow and causes anaerobic biology to take over, reducing nutrient cycling. When we leave the ground bare, we starve the soil of oxygen and invite disease and illness into our plants.

At Home and in the Suburb

Use ground covers between perennials, under shrubs, and around trees. Low-growing shrubs with ground covers underneath can cover slopes or flat areas, providing multiple canopy layers while still allowing for clear lines of sight.

In Veggie Gardens and Farms

Use cover crops like white clover, peas, oats, vetch, red clover, and rye. White and red clover can cover walking rows and in between veggie plants. Cover crops help grow plants with available nutrients in the soil due to their roots’ ongoing interactions with microbial life. 

If you see red nodules on your clover roots, you’re producing nitrogen in the soil. If you don’t see red nodules on your clover roots, that’s an indicator that your soil isn’t aerobic.

Bee atop a white clover flower

Tip #2: Minimize Disturbance

Human interference in the environment is the root cause of every global crisis. From climate change to ocean acidification, from mass extinction to ecosystem annihilation, human action is rapidly eroding the Earth’s physical and biological support systems.

We all want to do what is right when it comes to the environment, especially in our own yards. Healthy soil depends on eliminating pesticide use, tilling, plastics, and landscaping fabrics and practicing low-impact gardening instead.

Eliminate Pesticides

Pesticides (e.g., herbicides, insecticides, fungicides, nematicides, rodenticides—even organic pesticides) kill healthy soil microbes by directly poisoning them and creating anaerobic soil conditions. Since we’re trying to create aerobic conditions and grow aerobic microbes, we do not recommend any form of pesticide.

Instead, pull weeds by hand. Treat infected plants or soils with compost, worm castings, wood mulch, and liquid compost extract. Remove wasp nests with high-pressure water from a hose with a nozzle.

Eliminate Tilling

Tilling destroys fungal networks, rips apart earthworms and nematodes, and creates compact anaerobic conditions in the soil, encouraging weed growth. 

Turn areas by hand with shovels only once upon installation of new gardens and beds and only after topdressing with 3-6″ of compost. Turning will leave large clumps of soil intact, thus leaving webs of fungi, living nematodes, and other life forms to both inoculate and be inoculated by the freshly added compost. The newly turned-in fluffy compost will now sit under and around clumps of harder soil. After turning, cover immediately with mulch or more compost and then immediately plant or seed. Continue to put compost and plants or seeds into any bare areas until the ground is covered year-round.

Low Impact Gardening

Allow more weeds to grow in unused spaces and in the lawn. Bellflower, dandelion, creeping charlie, clover, black medic, purslane, and all weeds have soil-building capacity. Weeds also help keep the ground covered in green, keep roots in the soil, clean and cool water, and feed pollinators. Plus, many are edible!

Manage weed height by mowing or pulling them before they outgrow your garden plants. Over time, weedy ecosystems transition into shrubby ecosystems and then into ecosystems with trees. You can help this succession by selectively letting your favorite weeds grow in places where they work for you aesthetically.

Eliminate Plastics and Landscape Fabric

Nearly all soils worldwide are contaminated with microplastics, which have been shown to attract toxins in the soil at a 3-4 times greater rate than regular soil. This potentially poisons soil microbiology and creates anaerobic conditions.


Avoid using plastics in the landscape, including plastic edging, landscape fabric, plastic netting, plastic gutters, vinyl siding, and plastic plant pots and clean up plastic pollution when you see it.

Monarch butterfly collecting nectar from a pink flower

Tip #3 Keep Living Roots In The Soil

Plant roots foster the growth of beneficial soil microbes, infiltrate and filter groundwater, prevent erosion, slow down storm surges, and add organic matter to soils, all while supporting the plants we love.

Create Multiple Layers of Canopy

We want shallow roots mixed in with deeper roots. This looks like hardwood trees with shorter trees and large shrubs beneath them. Under and around the short trees and large shrubs can be shorter shrubs, perennials, and ground covers. Multiple canopy layers are not only good for soil health, but they also support birds and native pollinators while slowing and cooling rainwater.

Embrace Plant Diversity

Growing a diversity of plants will help us grow multiple layers of canopy while producing various roots with different types of soil-holding and soil-growing abilities. Plant diversity helps your landscape clean and filter water while remaining hardy in varying seasonal and weather conditions. Some plants do better in wetter soil, some in dry soil, and some in colder winters.

It’s best to have a mix of native and/or edible plants to grow healthy soil throughout Minnesota’s growing seasons.

Seeding no-mow fescue and Dutch white clover seeds can foster plant diversity and canopy layers. Let native, naturalized weeds (e.g., violets, Virginia waterleaf, black medic, wood sorrel, dandelions, and Creeping Charlie) grow. This can allow for multiple canopy layers that contribute to a greener lawn without watering in droughts and helps nurture soil to protect against erosion and runoff.

Mowing stunts root growth and limits plant diversity, so mow as little as possible, only once per month or once per season after the middle of August. This keeps weed trees from getting too big while allowing for deeper root growth!

Ground being tilled to create a new garden

Tip #4 Integrate Appropriate Fauna

How Animals Help

Integrating the right type and amount of animals and soil microbes into your landscape can help grow healthy soil. Many homeowners keep chickens, ducks, rabbits, and even goats, which helps create compostable manure and bedding. Field mice, voles, moles, rabbits, gophers, and squirrels help aerate the soil by digging tunnels. If animals are in spaces where you don’t want them, consider using live traps. Rabbits, squirrels, and deer may eat our garden plants, but they also help spread the seeds of important wild plants like wild strawberries, oaks, and cherries.

Birds are also excellent gardeners., helping plant serviceberry, chokecherry, sunflower, mulberry, and wild grapes. If the birds plant trees on your property, consider integrating them into your landscape to invite more birds!

Microbes: The Stomach of Plants

Microbes process and release nutrients right on plant roots, feeding and protecting plants from disease. The type of microbes you want to grow depends on which plants you want to grow. Generally speaking, we need to grow more soil fungi because our plants need a healthy variety of soil fungi as crop partners. Soil fungal growth can be easily harmed by compaction caused by common landscaping practices.

Other microbes—nematodes, testate amoebae, and microarthropods— are vital to soil and often absent from our grower-managed landscapes. Compost, bio-inoculants for nematodes, and types of mycorrhizal fungi introduce the appropriate microbial crop partners into soils.

Worms for Composting

Red wiggler composting worms are incredible allies in growing soil. They have soil microbes in their stomachs that they spread as they move through the soil profile. While some folks are rightly concerned about earthworms in northern forests, red wiggler worms can’t live through the winters in MN.

Inoculate outdoor compost piles with red wigglers every spring. Utilize worm castings much like you would use compost as an inoculant to help feed and protect plants. Larger earthworms dig deep into the ground and are good for your veggie garden, perennial garden, and lawns and can help restore damaged ecosystems. Just don’t bring earthworms of any type into forested areas.

Pollinators & Pets

Bees, butterflies, mosquitoes, flies, and many other insects pollinate flowers and allow plants to reproduce. What is good for plant health is also good for the soil. Encourage pollinators by having blooming native plants in your landscapes throughout the growing season.

Conversely, cats and dogs can interrupt our landscape. Dogs pace up and down fence lines and gardens, trampling and compacting the soil beneath their feet. To avoid soil compaction, it’s best to keep dogs out of gardens. Along fence lines and in dog runs, annually refresh thick layers of wood mulch to prevent compaction and erosion.

Dog urine also does major damage to lawns. If you have young dogs or a small lawn, consider removing it in place of wood mulch. Dog and cat manure (as well as humanure) are compostable, especially using red wiggler worms in piles mixed with 80% woodchip and kept at 50% moisture. However, it’s not legal in MN to compost these manures in your yard, and we don’t recommend it.

Robin parent feeding its checks in its window-side nest

Healthy Soil vs. Unhealthy Soil

Indicators of Healthy Soil

A vibrant, living ecosystem brimming with microorganisms, organic matter, and essential nutrients, here are the key characteristics of healthy soil:

  • Rich in Organic Matter – Decomposed plant and animal materials enrich the soil with nutrients.
  • Biodiversity – A diverse population of bacteria, fungi, earthworms, and insects work symbiotically to maintain soil structure and fertility.
  • Good Structure – Healthy soil has a crumbly texture and plenty of pores, allowing air and water to circulate freely.
  • Balanced pH Levels – Ideal soil pH ranges from 6 to 7, which provides a comfortable, conducive environment for most plants.
  • High Nutrient Availability – Essential nutrients like nitrogen, phosphorus, and potassium are right there, ready for plants to use!

Indicators of Unhealthy Soil

Unhealthy soil doesn’t have these essential characteristics. Instead, you’ll find:

  • Low Organic Matter – Depleted organic matter that results in poor soil fertility and structure.
  • Reduced Biodiversity – Fewer microorganisms and beneficial insects, which can lead to an imbalanced ecosystem.
  • Compaction and Poor Structure – Compaction limits root growth and reduces water infiltration and aeration.
  • Unbalanced pH Levels – Extremes in pH can make nutrients inaccessible to plants, inhibiting growth.
  • Nutrient Deficiencies or Toxicities – A lack of essential nutrients or the presence of toxic elements stunts plant development and yield.