This week's Garden Journey was to my backyard to make a batch of compost tea. I am a big fan of compost tea and I am constantly experimenting with new ingredients and different ratios. The idea is to get an explosion of the population of beneficial soil microbes in the compost tea mixture. Each liquid ingredient in the tea provides essential nutrients to soil microbes. The dry ingredients inoculate the tea with different types of microbes. The wormcastings are full of bacteria, the leaf mold is full of fungi and the finished compost will have a variety of other types of microorganisms. Different plants need different types of soil microbes to thrive, so having biodiversity in your tea is key. This backyard science experiement has worked for me in helping beef up weak plants, reverse disease issues and open up dense, compacted soil. The only thing that I have a problem with is using liquid humus, which is dervived from lignite, a type of low-grade coal. I am trying to illimate non-renewable resources from my gardening life, and using liquid humus goes against that principle. The liquid humus feeds fungal microbes so I will have to find something else to replace that. The molasses feeds the bacterial microbes and the fish and seedweed feeds everybody. Here's my current recipe:
4 gallons of water
aquarium bubbler for a small fish tank- I use a brick to weigh down the pumice stone
1 cup each of Fish Emulsion, Horticultural Molasses, Liquid Seaweed, and Liquid Humus.
1 pound worm castings (worm poop- I currently buy this at the nursery but I am planning to get pet worms soon)
1 pound finished compost- I use home made when I have it but I will use any bagged type too
1 pound or a couple big handfulls of leaf mold (leaf mold is just what it sounds like- get some moldy leaves off the ground from a wooded area- you can also use aged mulch, some bagged mulches are aged already)
cloth bags for dry ingredients- old socks, pieces of cloth tied with a rubber band etc will work.
Put the aquarium bubbler in your bucket of water. Add all of the liquid ingredients. Put the dry ingredients inside a cloth bag. Add the tea bag(s) to your liquid. Let it sit with the bubbler running for 24 hours. After 24 hours mix it with equal parts water. Rainwater is best but you can also use filtered water or tap water. It is better to do this imperfectly than to not do it at all. Try to use the finished tea within 8 hours. If you can't use it right away you can leave it in your bucket with the bubbler running and add more of the liquid ingredients every day until you are ready to use it.
To apply- I just use buckets and watering cans to dump it on the ground. If you are more frugal and patient than I am you can use a pump up sprayer and spray every inch of your yard using just a few gallons. Really one gallon of concentrate mixed with one gallon of water will cover a normal city sized yard with a light mist. I find it more satisfying to dump it on the ground and I just make more all the time. Watering the ground beforehand will help it soak in, but again, it's better to do this imprefectly than not at all so don't get too caught up innthe details. I toss the used tea bags into my compost pile and it really speeds up the compost pile breakdown!
Bucket with aquarium bubbler plugged in- you can see the tea bags and the brick in the bucket. The bottles of liquid ingredients are in the background.