How to Brew Compost Tea
What could be better than composting and returning organic matter to the soil? At stimulating plant growth and at preventing disease? Emily Gatch, from Seeds of Change in New Mexico, has an idea brewing.
"Compost tea is a wonderfully nourishing substance that you apply to the surface of plants or to the soil," she says. "It takes the goodness that's in compost and extracts it in water so that you have a solution that you can use a number of ways in your garden."
Compost tea actually enhances the benefits of compost with one simple addition - oxygen.
How to Make Compost Tea
Gather the brewing supplies. Before you start brewing your compost tea, you'll need a few supplies. You can find commercial products to help you do the job, or you can make your own system. All you need is a 10-gallon bucket and an aquarium pump. The most important things, of course, are good quality compost, a water source, aeration and some compost catalyst for good measure.
Fill your bucket with water. If you're using tap water, let it sit for a day in the bucket. This allows the release of chlorine, which could otherwise kill beneficial micro-organisms.
Add the catalyst. Dump the compost catalyst into the bucket. The catalyst is a commercial mixture of nutrients that essentially wakes up the micro-organisms in the compost and encourages them to multiply
Float your compost. Put the compost in a "sachet" in the bucket. A sachet? Think of the wire-mesh containers used in brewing the tea you drink. (If you don't have a compost pile at home, bagged compost from your garden center is a fine alternative.)
Pump it. "The pump is the final step to starting the brewing process," Emily says. "It pumps air up through the bottom and throughout the solution. It's essential for the beneficial fungi and bacteria in the compost to start working."
For 24 hours, air pumps through the compost tea. The finished product is a rich, frothy brew. The foam is an indication of the nutrients, bacteria, fungi, nematodes and protozoans that are going to do their work on your plants. And there's no wasting anything from the brew; the solid compost can still be spread in the garden.
How to Use Compost Tea
The tea itself is best used soon after brewing. Any longer than a day or two and the organisms begin to use up all the oxygen they've just been fed.
Spray the tea on leaves. Foliar applications of compost tea are absorbed more quickly and distributed throughout the plant more efficiently than soil drenchings. Spraying the leaves also helps to lower the incidence of nasty diseases like powdery mildew.
Feed the soil. You can also feed plants by feeding their soil. Emily uses compost tea on seedlings. A good drenching right after the seedlings have been transplanted will help fight soil-borne diseases.
When and how often? Whether you spray the soil or the leaves, the best time to do it is in the morning or evening, when plants can best absorb the nutrients. Repeat sprays about once a month throughout the season.
Over time, you can build up your soil and reduce the need for other kinds of fertilizers, so compost tea is also a money saver (as if you needed another reason to try it out).