In today’s gardening world, “compost” is often used as a catch-all term for anything dark, crumbly, and sold in a bag. But don’t be fooled. Compost quality varies wildly—and using the wrong kind can quietly undermine your garden’s health and productivity.
At Deep Roots Project, our innovative Transformative Gardening method is built on a simple truth: your soil is only as good as the microbial life within it. And the microbial life depends entirely on the quality of compost you use.
Microbial Powerhouse in Deep Roots Compost
Our 100% microbe- and nutrient-rich compost is not just soil—it is the growing medium. Instead of filling beds with conventional “topsoil” or store-bought potting mixes that often lack life, we fill our raised beds with compost made through a thermophilic (heat) process using only organic matter from plants and manure from herbivores. This heat process destroys weed seeds and harmful pathogens while nurturing beneficial microbes and fungi. These living organisms then create an underground ecosystem that feeds your plants naturally, reducing the need for synthetic fertilizers.
When we add organic worm castings (vermicompost), our microbial populations explode with diversity and strength, increasing nutrient availability and plant resilience even further.
In contrast, many bagged retail composts are mostly ground-up wood chips and tree bark—byproducts of the lumber industry. These materials are low in nutrients, often still decomposing (which robs nitrogen from your plants), and nearly devoid of microbial life. Yet, they’re marketed as “organic” simply because they come from trees.
A Warning About Toxic “Composts”
Perhaps the most dangerous composts are those made from sewage sludge, commonly marketed under green-sounding names like “biosolids” or “recycled waste.” These materials come from municipal wastewater treatment plants and contain far more than just human waste.
Sewage sludge can include:
• Heavy metals (lead, mercury, arsenic, cadmium)
• PFAS (“forever chemicals”) linked to cancers and hormonal disruption
• Pharmaceuticals and hormones (from medications flushed down the drain)
• Microplastics
• Pathogens like E. coli and Salmonella
Though these biosolid products are legal to sell in many areas, they pose serious risks to human health, soil microbiomes, food safety, and local water supplies.
That’s why Deep Roots will never use biosolids, and we encourage you to avoid them, too. Always ask what’s in your compost.
What About Free Municipal Compost?
We understand that buying premium compost isn’t always in everyone’s budget. Some gardeners rely on free municipal compost, which is typically made from leaves, grass, and brush. This compost isn’t harmful, but it’s usually low in both nutrients and microbial life compared to Deep Roots compost.
Here’s a great solution: You can safely use municipal compost if you mix in our top-quality worm castings. This combination boosts microbial activity and improves nutrient availability. While not as effective as using 100% Deep Roots compost, it’s a strong compromise when budgets are tight.
Why Deep Roots Compost Is Worth It
Compared to most retail options, our compost is:
• More nutrient dense
• More microbially active
• Free from toxic materials
• OMRI and USCC certified for organic food growing
Yes, Deep Roots compost may cost a little more. But it’s a small investment that pays off in healthier plants, bigger harvests, and safer soil.
Bottom Line: Not All Compost Is Equal.
Your garden—and your health—deserve better than compost made from industrial waste or bark chips. Choose compost that supports soil life, not destroys it.
Choose Deep Roots Compost.
Join the Deep Roots movement
We’re not just about gardening; we’re about changing the way people grow food. Whether you have a tiny balcony or a full backyard, we’ll help you grow like a pro.
Stay in the loop: Signup for our email newsletter. If you also provide your phone number you will get text message updates that link to our best blog posts.
Get involved: Attend a free workshop, become a volunteer, grab a raised bed, or simply follow along for expert tips. Contact our support team any time you have a question at 708-655-5299 and support@deep-roots-project.org.
Learn. Share. Grow. Volunteer: We invite you to be a part of our sustainable movement right here in our own backyards! We want all our volunteers to have fun and learn while they contribute to expanding the Deep Roots community. We can customize a volunteer assignment to your time, interests and skills. Learn more on our Volunteer page
Let’s make this your most delicious year yet!
Dive Deeper
Click on the Blog Posts Below for more about our Innovative methods.
Beautify Garden with Our Cedar Raised Beds!
Our Deep Roots handcrafted cedar raised beds are designed to endure outdoors while adding a touch of style to your yard. As a bonus, they are the perfect depth to hold just the right amount of our nutrient-rich compost growing medium, which comes free with each bed.
Deep Roots Supports Gardeners
We provide our gardeners with the best products for success – like cedar raised beds, microbe-rich compost and microbe-rich worm castings. Check our online store. Always talk to our customer support team before placing your order online. If you need help or have a question contact us at support[at]deep-roots-project.org and 708-655-5299.
Deep Roots Online Store
See our online store for details about prices, ordering and delivery of raised beds, planter boxes, microbe-rich compost, worm castings, leaf mulch and more. We don’t sell traditional soil, since we use 100% compost as our growing medium. Our online store has 2 sections – (1) raised beds and planter boxes and (2) compost, worm castings, fertilizer.
Please contact our customer support team before placing an order online so we can assist you with the details and answer your gardening questions. You can pay by credit card in the store or by check.
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