Making Compost Extracts
One pound of compost becomes a feast for the whole garden.
Wow! I have waaaaaaaay too much high-grade compost!” said no gardener ever. Generating that much rich, dark garden goodness evades the majority of even the highest level soil celebrity.
Base-level compost has plenty of organic matter. However, the really good stuff has the humus plus a plethora of beneficial microorganisms: beneficial bacteria, fungi, protozoa and nematodes.
The difference between “top shelf” compost and “well” compost is entirely dependent on the populations and diversity of the microorganisms it contains. High-grade compost is precious.
I’m here to show you how to turn that little bit of compost into a huge boost to your entire garden.
The Boss Move when using compost is not only to add organic matter but to reinforce the levels of beneficial microorganisms in the soil. Plants will go to great lengths to cover every root surface (rhizosphere) and stem and leaf surface (phyllosphere) with beneficial microorganisms, as a surface coated with allies is impenetrable to adversaries. By reinforcing the front lines with these “good guy” microbes, we protect our plants from disease and pests and help them become more resilient to environmental stressors.
I’m a huge advocate of compost tea. But making a high-quality compost tea is difficult and time-consuming. On a recent trip to the Caribbean to teach and learn from farmers there, I faced a challenge: Many farms there didn’t even have electricity. Without electricity, there was no tea brewing, as we couldn’t use air pumps to force oxygen into the water. Searching for the solution, I pored over my notes from years of study and found the answer. I was smacked with the simple elegance of the solution: the compost extract. You simply cannot bungle a compost extract.
How does this work? The levels of beneficial microorganisms in high-quality compost are up to 10 times higher than the levels in even the healthiest of soils. That means a small amount of compost can feed a much larger area than if it were used for topdressing (applying a thin layer of compost directly to the surface of a garden bed), and the application is much easier. Rather than bending over and crawling around your garden spreading compost, you can stroll around with a watering can in one hand and a cocktail in the other, straight booshing your beds with microbial goodness. Boss Move again.
You can do it
Step 1. Start with a five-gallon bucket of dechlorinated water. Think about it: Chlorine is added to municipal water to kill microorganisms, and we want to extract and preserve microorganisms; so let’s get that stuff out. Fill your bucket the night before and the chlorine will evaporate out. Or use the rainwater you’ve harvested and stored, and give yourself a high five from me. Thanks for being a next-level human.
Step 2. Place 1/2 to 1 lb. of high-grade sifted compost* in a paint strainer bag (budget) or compost tea bag (baller; www. composttealab. com/store/; $24-40). Submerge bag in the bucket of dechlorinated water and massage for up to one minute. (The majority of the organic acids and microbes will release themselves from the compost and enter into suspension in the water; massaging past this point only expends energy without increasing results.) Boom, easy breezy.
* The finished compost at the bottom of an old neglected compost pile will beat a bagged product any day, but making compost extract with any compost is better than not doing it at all. Even in commercial composts where a lot of the organisms are dead, the user will extract useful organic acids at a fraction of the cost of buying supplements. Regarding bagged composts, Miller’s has been the best I’ve looked at under the microscope, most likely due to the fact they are local.
Step 3. Transfer from the bucket to your favorite watering can. You want to make sure your garden beds are pre-moistened, as inviting your microbes to a bone-dry environment makes you the worst of hosts. This also helps to remind you that you aren’t trying to water your plants, you are applying microbes to your soil. A heavy dose of compost extract looks like one gallon per 50 square feet, although you can push this to 200-400 square feet, depending on the quality of your compost.
Apply at least three times a season; I know growers who water with compost extract, every time.
Curious about the quality of your compost? I’m here for you, we are all in this together! If you are a contributor to CATALYST Magazine or Wasatch Community Gardens, bring a sample of your compost to the Green Team Farm and we’ll look at it under the microscope together. The address of the farm is 622 W. 100 South, in downtown SLC. Not a donor yet? Pehaps it’s time you made a Boss Move of community support. Visit our websites: www. Catalyst Magazine.net and WasatchGardens.org.
Step 4. You’re done. Seriously. It’s that easy.
Happy growing. See you next month.
James Loomis is the Green Team farm manager for Wasatch Community Gardens.