Compost Tea

Compost is wonderful stuff. It increases the health and vitality of your soil, thereby increasing the health of your plants. It does this primarily by feeding the beneficial microbes in the soil. When they become active, they make all kinds of good things. Add to this all of the major and minor nutrients that compost contains and it is practically the perfect supplement for your plants. There’s just one problem. Compost takes a long time to make. Okay, two problems. For every pound of raw material you put in, you only get a few ounces of finished compost. So you work hard all summer collecting table scraps, lawn clippings, and garden trimmings and you work hard all fall collecting all those fallen leaves. You fill the compost bin several times over, yet somehow by spring you only have enough to provide a sparse top dressing to your garden. Wouldn’t it be great to be able to make some sort of “compost concentrate” that you could apply or even get something that you can apply weekly? Well, it turns out that you can. It’s called compost tea.

Compost tea is a liquid version of compost that you spray on your plants as a foliar spray as well as pour on the soil around the plants. It is full of both beneficial nutrients and beneficial bacteria. Compost tea increases overall health of the plant and increases the thickness of the cuticle of the leaf, helping the plant better resist fungal and bacterial diseases. It also helps the plant better fend off insect predators. Best of all, it’s easier to make than you might think. There are many recipes out there, but after some research and experimentation, I have come up with my version that seems to work quite well for me.

First of all, you need materials:

Hardware
5 Gallon Bucket
Aquarium air pump with hose and diffuser
Filter (I use knee-high nylons)

Software
Water (Rainwater or filtered tap water. Chlorine=Bad)
Finished Compost
A few tablespoons of molasses

Procedure
Fill the bucket with the water. Fill the nylon with compost. I don’t have a hard-and-fast rule about how much, but a cup of compost per gallon of water is probably a good rule of thumb. Put the compost filled sock in the bucket and add the molasses. Hook up your pump, put the diffuser in the bucket and turn it on. After a half hour or so, you will start getting some foam on the top. This is a good thing. Soil-borne bacteria produce all kinds of by-products that act as a glue to hold the soil together. My guess is that these compounds are what is causing the foam. At any rate, it is a sign that you have good microbial action going on. Let it sit and brew for about 24 hours. A little more or a little less is fine, but I would let it brew at least 12 hours and probably no more than 48 hours. When it is done, spray it on your happy plants. The used compost can go back in the compost bin or straight on the soil.

There is one very important thing to remember about compost tea, though. It’s alive! If you let it sit around more than about 24 hours, the good bacteria might die and the bad ones might take over, so use it quickly.

For the sufficiently advanced bioneer, compost tea seems like an ideal medium for applying other supplements, like maybe a little garlic to help fend off herbivores. I haven’t begun experimentation of this yet, but it is on the docket. Stay tuned!