by Hayes Martens
Owner and lead ecological designer at Michigan Landscapers, LLC
Most folks walk across soil every day and think nothing of it. It’s just dirt, right? Something to plant in, mow over, or maybe get under your fingernails. But here’s the thing—soil is alive. More alive than most people realize. Beneath our feet, there’s a whole world at work: bacteria, fungi, tiny grazers. They’re running the show whether we notice them or not.
The soil microbiome isn’t just important. It’s essential. Without it, plants struggle. With it, they thrive. These microscopic workers build soil structure, unlock nutrients, hold moisture, fight off diseases, and even help pull carbon out of the atmosphere. They’re not background noise—they are the main act. And if we ignore them, we’re missing the biggest lever we have in sustainable landscaping.
So, what I want to do here is pull back the curtain on this underground world. We’ll look at who these microbes are, what they do day in and day out, and most importantly, how people like us—whether you’re managing landscapes for a living or just trying to build better soil at home—can give them what they need to succeed. Once you see what’s happening underground, you’ll never look at soil the same way again.
Soil Microbiology
Let’s start with the basics. What is the soil microbiome, really? Think of it as the engine room of your landscape. It’s a living network packed with billions of bacteria, fungi, protozoa, nematodes, archaea, and a few other microscopic players. They all have different jobs, but together, they keep your soil alive and your plants thriving.
Bacteria—The Workhorses of the Soil
Bacteria are the heavy lifters. They break down organic matter and make nutrients like nitrogen, phosphorus, and potassium available to plants. Some bacteria, like nitrogen-fixers, even pull nitrogen straight from the atmosphere and feed it right to the roots.
What can you do to support them? Feed them. Good compost is gold here. Compost brings both organic matter and a fresh batch of microbes into your soil. Planting cover crops like clover and vetch during the off-season keeps the soil covered and gives bacteria a steady food supply through their root exudates. Also, skip the chemical fertilizers when you can—they push the microbial balance out of whack, and trust me, I’ve seen landscapes decline fast when synthetics take over.
Fungi—Nature’s Underground Network
If bacteria are the workhorses, fungi are the architects. They build pathways that connect plant roots to far-off water and nutrients. Mycorrhizal fungi are the best-known example. They wrap around plant roots and trade nutrients for sugars—a win-win relationship that strengthens both sides.
Want to grow more beneficial fungi? First, lay off the tilling. Tillage breaks up fungal networks like a plow through water lines. Use wood chips or leaf mulch to give fungi the carbon-rich material they love. And you can go a step further by using a mycorrhizal inoculant when planting. It gives fungi a head start in colonizing your soil.
Protozoa, Nematodes, and the Rest of the Crew
Protozoa and nematodes are the grazers of the microscopic world. They feed on bacteria and fungi, and as they do, they release nutrients in forms plants can absorb. But—and it’s a big but—not all nematodes are friendly. Some go after plant roots and cause real problems.
To keep the balance in your favor, focus on soil diversity. Healthy, living soils naturally keep pests in check because beneficial microbes outcompete the troublemakers. Aerated compost teas are a good addition here, too. They boost beneficial populations and tip the scales toward soil health.
At Michigan Landscapers, LLC, we’ve seen how a healthy, diverse soil community can transform stubborn, compacted soils into thriving, self-supporting landscapes. The difference is night and day.
The Rhizosphere—The Hotspot of Life
Right around plant roots is the rhizosphere. This is where the action happens. Plants pump out sugars and organic compounds to attract microbes, and in return, the microbes feed and protect the plants. It’s like a bustling farmer’s market, with constant trade and exchange.
To build a thriving rhizosphere, use amendments like humic acid, seaweed extracts, or biochar that create the right conditions for microbial life. These help plants attract the right microbial partners and keep that underground economy humming.
Communication & Symbiosis—How Plants and Microbes Talk
Believe it or not, plants and microbes are in constant conversation. Through chemical signals, plants can “ask” microbes for help finding nutrients or fighting off pests. In return, microbes get the energy they need to survive. This natural teamwork boosts plant health and keeps the whole soil ecosystem in balance.
By supporting this communication line—with healthy soils and the right organic inputs—we’re not just growing better plants. We’re setting up whole ecosystems to thrive, from the ground up.
Ecological Benefits of a Healthy Soil Microbiome
When your soil microbiome is firing on all cylinders, the benefits don’t just add up—they multiply. What you get is a chain reaction. Start with soil life, and watch everything else in your landscape improve. Healthier plants, fewer pests, better moisture control—you name it.
Nutrient Cycling & Bioavailability
Microbes are the bridge between raw materials in the soil and the nutrients plants can actually use. Without them, minerals and organic matter just sit there, locked away. With them, it’s a whole different story. Bacteria and fungi break things down, release nutrients, and help them stick around longer.
What can you do? Feed your soil with compost, use cover crops in the off-season, and ease up on the synthetics. Quick-hit fertilizers might green things up fast, but they cut out the biology. Build your soil life, and you build lasting fertility.
Soil Structure & Water Retention
Good soil has texture. It crumbles, it breathes, it holds water but drains well. You know it when you see it. Microbes help build that structure by creating tiny glues and webs that bind soil particles together. Fungal threads, bacterial biofilms—they’re the unseen builders.
What helps? Biochar is fantastic here. It acts like a microbial apartment complex, giving them space to work. Reduced tillage is another big win. Every time you till, you’re ripping apart the structure they’ve worked hard to build. And mulch? It keeps moisture in and feeds the builders at the same time.
Disease Suppression
A thriving microbial community acts like a security team for your plants. Beneficial microbes crowd out the bad guys, outcompete with them for resources, and some even attack pathogens directly. Certain fungi and bacteria create natural antibiotics that keep harmful organisms in check.
How do you help? Use compost teas rich in beneficial organisms like Bacillus subtilis, Trichoderma species, beneficial nematodes, and mycorrhizal fungi. You can find these in a few places, and it’s simpler than you might think.
Many reputable compost tea brewers and soil amendment companies include these organisms in their biological blends. Look for products labeled as “biological inoculants” or “microbial soil conditioners.” Brands like BioAg, Earth Alive Soil Activator, Dr. Earth, MicroLife, and Extreme Gardening’s Mykos often include these species. Some organic-focused garden centers even carry pre-brewed compost teas containing Trichoderma and Bacillus subtilis—worth asking about locally.
Another good option is picking up mycorrhizal inoculants or biological fungicides. These are often designed with disease suppression in mind and usually include both Trichoderma and Bacillus subtilis. A few solid examples: Companion® Biological Fungicide (which is Bacillus subtilis-based), RootShield® (Trichoderma harzianum strain), and MycoApply® Endo/Ecto Mix, which covers a wide range of beneficial microbes.
And if you’re the DIY type, brewing your own actively aerated compost tea (AACT) is an excellent way to grow these beneficial microbes naturally. Use high-quality, biologically active compost—Trichoderma is especially common in well-made leaf mold compost, and Bacillus subtilis thrives in thermophilic compost environments and worm castings. A good brew not only multiplies these organisms but also delivers them right to your soil in peak condition.
Beyond inoculants and teas, plant a variety of species to promote microbial diversity. And stay away from harsh chemicals that wipe out your soil life along with the pests. When the good guys are strong, you’ll need the spray bottle less and less.
Carbon Sequestration & Resilience
Healthy soil isn’t just good for your landscape—it’s good for the planet. Microbial life plays a massive role in capturing carbon and storing it underground. Fungi, in particular, help lock away carbon in stable forms that last for decades, even centuries.
What can you do? Plant more perennials. Keep living roots in the soil year-round when you can. Feed your fungi with organic mulches and let them do the heavy lifting.
Biodiversity Support
Soil life doesn’t stop at microbes. When you get the microbial community thriving, you’ll see the benefits ripple out. Healthier soil attracts worms, insects, birds, and pollinators. It’s all connected.
Want more life in your landscape? Go for diversity in your plantings. Layer plants to mimic natural ecosystems. Use natives whenever possible—they’ve evolved alongside local soil life. Keep natural debris on the ground, and rotate what you grow to keep the system in balance.
Here’s the bottom line: when you care for the life in your soil, it pays you back. What starts as a handful of microbes turns into a full-blown ecosystem that works for you every single day.
Conclusion
At the end of the day, soil biology isn’t just a technical detail—it’s the backbone of every successful landscape. When we think about healthy plants, thriving gardens, or resilient ecosystems, it all starts underground. If the biology isn’t there, you’re fighting an uphill battle. But when you build and support life in your soil, the landscape works with you, not against you.
The beauty of it is, you don’t need to be a scientist to get this right. Small shifts in how you manage your soil can make a big difference. Feed it with compost and organic matter. Avoid tearing it up with heavy tillage. Keep it covered, keep it diverse, and let the biology do its job. Nature already knows what to do—we just have to give it the chance.
So, the next time you’re out in the garden or walking your property, take a moment to think about the life below your feet. Support it, and you’ll build landscapes that are not just beautiful, but built to last. That’s the real power of working with soil biology.
At Michigan Landscapers, LLC, this approach guides every project we take on. Whether it’s residential/commercial landscaping or larger ecological restorations, we treat the soil as the starting point for long-term success.
Hayes Martens has been in the lawn and landscape industry for 39 years. He is the owner and lead ecological designer at Michigan Landscapers, LLC. Hayes studied Horticulture and Turfgrass Management in college, and today, he and his team specialize in sustainable landscape design and soil health solutions for residential and commercial properties across the Midwest. His work focuses on improving biodiversity, using environmentally friendly materials, and building landscapes that thrive naturally through the seasons. Find more of his blogs at milandscaper.com/blog
