Tea connoisseurs know there are good cups of tea out there as well as bad, and that it all starts with the leaf. The same can be said for compost tea. In order to get the full probiotic and fungal benefits of a good compost tea, you need to start with healthy, active compost. So, no matter which compost tea recipe you choose, be sure to start with good ingredients.
Compost tea (defined as a liquid suspension or solution made from steeping compost in water) can be used either as a foliage spray or as a soil-drench. It is highly useful as a slow-release organic fertilizer, and helps greatly to improve soil structure. It is also effective in helping to protect plants against diseases and improve nutrient uptake.
The active microbes from the compost, such as bacteria and fungi, are transferred to the water when the tea is steeped. They are then transferred to the plant when the compost tea is sprayed or poured. These ‘friendly’ microbes discourage less desirable bacteria and fungi from growing on leaves and roots and the tea can even be sprayed onto plant wounds to prevent unpleasant infections.
Another thing to think about before making compost tea is figure out the special needs of plants you will use it on. Some plants and trees prefer fungal-dominated compost tea, while others, such as vegetables and grass, prefer bacteria-dominated compost tea. Do your research on your individual needs before getting started.
If you are building your compost from scratch, you can add fungus promoting ingredients such as paper products and sawdust, or bacteria promoting ingredients such as kitchen scraps. (In truth, good compost is going to have a mix of both–but you can adjust the quantities to suit your purposes.) You can also add ingredients to the compost tea mixture itself to promote one thing or the other.
How to make compost tea
Ready for a good compost tea recipe? Try this:
- As previously mentioned, be sure to start with mature, healthy, active compost. It should have been allowed to decompose fully, with a minimum of large lumpy material.
- If you are using city water, You don’t want chlorine in your compost tea, as this could kill beneficial organisms. Let the water sit in a bucket for about 24 hours as this will allow the majority of chlorine to evaporate out of the water. You can speed this process up by aerating the water with bubblers for around 4 hours.
- Fill a 5 gallon bucket half full of compost. Fill the bucket with water to within three inches of the top.
- Give the mix a stir and then begin aeration of the mixture. This is very important for increasing microbial growth in the mixture. It is often done with a compost tea brewer. But if you don’t have one, you can provide aeration with a simple aquarium pump attached to some plastic tubing and aeration stones, all of which are readily available at the local aquarium hobby shop. Be sure the stones are at the bottom of the bucket to ensure maximum movement and aeration of the solution.
- You can add ingredients to the compost tea as it is brewing to promote either bacterial or fungal growth. For example, add fish oil or seaweed to increase fungal activity. To increase bacterial growth, add 2-3 tablespoons of unsulfured molasses to the mix. Honey, sugar and maple syrup can also be used.
- Like any tea, the longer it steeps the stronger it is. However, if you are steeping for anything longer than three days, be sure to feed the mixture with molasses or something equivalent so that the bacteria remain active and don’t die off.
- Stir the tea a couple of times a day to ensure it is well mixed and to further promote aeration.
- Finally, you may want to strain it. If you are planning to use the compost tea as a soil-drench, there’s no need to strain it so just use it directly on the soil. If you are instead planning to use the compost tea as a foliage spray or otherwise plan to apply it with a sprayer, you will need to strain it so as to remove the solid matter. You can use a pillowcase, old nylon stocking, tea towel or cheesecloth. Just be sure the material you use hasn’t been treated with any chemicals that could kill the activity of the compost tea.
Once it’s ready, you should use the compost tea immediately instead of letting it sit.
So is compost tea all it’s ‘brewed’ up to be?
There seems to be some debate as to the effectiveness of compost tea. Some people note a lack of scientific evidence of its benefits and claim it is another money-making scheme to encourage the sale of compost tea brewer devices. On the other hand, there are plenty of gardening experts who claim a long list of benefits and share their coveted compost tea recipes. However, I think everyone can agree that so long as the compost tea is active and healthy, it can’t possibly hurt!