In sustainable gardening and farming, one of the most powerful resources you can use is already available on many farms—animal manure. But to unlock its full potential, it needs to be fermented properly. Raw manure can do more harm than good if applied too early. Fermentation turns it into a nutrient-rich, safe, and effective fertilizer that nourishes your plants and improves soil health.
This guide will walk you through why and how to ferment manure correctly, helping you reduce costs, cut down on pesticide use, and grow healthier crops with less effort.
Why Ferment Animal Manure?
Raw (unfermented) manure may seem like a quick solution for soil fertility, but it comes with several drawbacks:
High ammonia content can burn plants
Weed seeds and pathogens may still be active
Unbalanced nutrient release can cause plant stress
Increased need for pesticides due to disease-prone plants
When properly fermented, manure becomes:
Safer for plant roots
Rich in beneficial microbes
Easier to apply and integrate into soil
Environmentally friendly, with reduced runoff and odor
In short, fermentation transforms waste into a goldmine for your garden.
Step-by-Step Guide to Fermenting Manure
Whether you’re working with cow, horse, goat, or chicken manure, the basic fermentation process is the same. Here’s how to do it right:
- Gather and Pile
Start by collecting fresh manure and forming a compact pile in a designated composting area. For best results, mix in a bit of straw, sawdust, or dried leaves—this balances carbon and nitrogen levels.
Avoid spreading the manure thinly across a wide area. A consolidated pile helps retain heat and speeds up decomposition.
- Lightly Water the Pile
Moisture is essential for microbial activity. Gently water the pile so it’s damp—not soaking wet. You should be able to grab a handful and feel some moisture without water dripping from it.
Proper moisture levels encourage good bacteria and fungi to break down the organic material efficiently.
- Cover the Pile with Plastic
Use a plastic sheet or tarp to cover the pile. This:
Traps heat
Retains moisture
Speeds up microbial action
Prevents nutrient loss through evaporation or leaching
Make sure there’s a little air flow to avoid anaerobic conditions, which can produce foul odors and slow fermentation.
- Let It Ferment for 2–3 Months
Over the next 2 to 3 months, the pile will heat up and begin to break down. During this period:
Turn the pile every 2–3 weeks using a pitchfork or shovel. This introduces oxygen and ensures even decomposition.
Monitor the temperature—ideally it should reach 130–150°F (55–65°C). That’s hot enough to kill harmful pathogens and weed seeds.
You’ll notice the pile becoming darker, crumbly, and less smelly as it matures.
Need Faster Results? Try Hot Fermentation
If you want usable fertilizer in under two months, you can speed up the process:
Make smaller piles, no taller than 2–3 feet
Position them in a sunny spot to retain heat
Turn more frequently—every 7 to 10 days
Use fermentation accelerators like EM (Effective Microorganisms) or a handful of mature compost to jumpstart microbial growth
With good sunlight and active turning, your manure can be ready in 50 to 60 days.
Tips for Using Fermented Manure in the Garden
Once your manure is fully fermented, it’s time to put it to work:
Mix it into garden beds before planting
Side-dress vegetables during growth for a nutrient boost
Add to compost teas for enhanced feeding
Top-dress fruit trees and shrubs in early spring
Avoid using it on seedlings or freshly transplanted plants right away. Even fermented manure can be too rich for delicate roots—let them establish first.
Final Thoughts: Healthy Soil Starts with Smart Choices
Fermenting animal manure is one of the easiest and most cost-effective ways to enrich your soil naturally. By following these simple steps, you’ll reduce your dependence on chemical fertilizers, lower labor costs, and grow healthier crops that require fewer pesticides.
It’s a win for your garden—and the planet.