Compost tea is the drink of champions! Not for us of course, but for our plants. Nutrients are continually leaving your soil through harvesting, rain, soil erosion and tillage. Compost tea is like a quick dose of vitamins and minerals that puts these nutrients back into the ground to help plants grow and thrive.
Making compost tea involves filtering your existing compost to extract nutrients for your plants that they can readily use. But it isn't just a quick-fix. It should be a part of your long term strategy to increase the overall health of your soil. That's because compost tea not only makes plants more productive but also better able to ward off diseases.
The best compost tea recipe doesn't have to be complicated. In fact, if you have compost, a bag, and a bucket, you can get started straight away. That said, you can tweak your recipe a bit to best serve the plants you are feeding.
Below are a few recipes you can try, whether you need a simple classic for a few ornamentals or a heavy-duty solution that can feed your entire farm.
How Does Compost Tea Work?
You may be wondering why you should use compost tea when you already add compost to your soil. Adding compost to your garden adds nutrients to the earth, but it's part of a long-term maintenance process.
On the other hand, compost tea delivers all of those beneficial nutrients you get in compost, only faster. That's because when you add compost to water and let it “brew,” it steeps out the nutrients and makes them more available to the plants. Kind of like a vitamin makes certain elements more available to your body.
Benefits of Compost Tea
In her book The Compost Tea Brewing Manual, Dr. Elaine Ingham says that compost tea contains thousands of beneficial bacteria and microorganisms. Compost tea also includes the big three nutrients nitrogen, potassium, and potash (NPK), which are essential for building healthy plants. A good compost tea recipe lets you:
- Improve plant growth.
- Replace commercial fertilizers.
- Save money.
- Build better soil.
Basic Compost Tea Recipe
There are many ways of making compost tea. One popular approach is to use vermiculture casting. If you don’t already have a worm bin going, this is yet another reason to start one. Even if you haven't started your worm compost yet, you can still make a healthy tea.
- Pillowcase or empty bag from rice or wheat
- String or baling twine
- Five-gallon bucket
- Rinse out the bucket with plain water – you don’t want any residue bleach or soap in the bucket.
- Put one shovel full of compost inside the pillowcase.
- Tie it shut tightly with the string.
- Place the bucket in a sunny location.
- Fill the bucket two-thirds of the way with water.
- Let it sit and “brew” for 3 days.
After brewing, your compost tea recipe is complete. Take out the bag and empty it back into your compost. Now you can use the tea to water your plants.
Adjusting Your Tea
More Bacterial: Some plants, like brassicas, veggies, and grasses prefer a more bacterial tea. To increase bacteria, use 10 parts worm castings with 1 part sugar (molasses or cane sugar is perfect) for your compost in the recipe above.
More Fungal: If you are feeding trees primarily, adjust your compost tea recipe to be more fungal. Use 20 parts fungal-dominated compost, or add mycorrhizal fungi to your compost. Combine with 1 part ground oatmeal and use as your compost in the recipe above.
Compost Tea Brewer
If you are finding that the basic compost tea recipe doesn’t meet your needs and you need a more continuous supply, try making a 5-gallon compost tea brewer using the directions in the video below. Five gallons of tea will feed a 5,000 square foot garden.
If you need a lot of compost tea, you can also make the large 25-gallon bucket compost brewer featured in the video below.
Super Duper Compost Tea Recipe
This compost tea recipe comes from the Smiling Gardener. This is a super duper organic compost tea recipe that was adapted for a five-gallon homemade compost tea brewer. This takes several days to make and uses liquid fish and kelp fertilizers to give it an extra nutrient boost.
The compost tea recipe ingredients are:
- Two cups good, aerobic, nice-smelling, fully finished organic compost
- One tablespoon un-sulfured blackstrap molasses
- One tablespoon organic liquid kelp fertilizer
- One teaspoon organic liquid ﬁsh fertilizer
Process this recipe the same way you did with the basic recipe.
Tips For the Best Compost Tea Recipe
- Use well water or rainwater. City water often contains chlorine and or ammonia to kill germs that are bad for humans. However, this also kills your nutrients and beneficial bacteria. If you only have access to city water, place the water in a bucket and let it sit for 24 hours before you add the compost bag. This allows the chlorine to evaporate out.
- If your compost tea starts to smell sour, then it is not getting enough oxygen. You can do one of two things. Stir it with a slated spoon like you would your soup. You can also add an aquarium air pump and feed an airstone into the bucket.
- Add some sweetener like molasses, honey or brown sugar. This will feed your bacteria and fungi, which will grow and divide, and create even more nutrients for your plants.
- Don't use fresh manure for compost tea. Manure that has not been composted will be high in nitrates that could burn your plants. Also, fresh manure may contain pathogens such as E.coli that are unhealthy for you and the plants.
A Note on Compost Quality
The quality of your compost is critical. Make sure you are using a layering system of greens and browns that encourages the growth of microorganisms and earthworms.
Your compost should contain animal manures, straw and even some additional nutrients such as rock phosphate powder and/or wood ashes. During the composting process, these will all be mixed together naturally by your worms and other organisms.
When you add a good homemade compost into the compost tea recipe, you end up with a superior fertilizer.
Applying Your Compost Tea
You can use your compost tea in two ways. The most obvious way is to water your plants with the tea. Simply soak the ground around the base of the plant and the water in the tea will carry the nutrients down to the roots.
The second method is to apply the compost tea as a foliar spray. In this method, you will transfer your tea mixture to a sprayer. Then, preferably in the early morning, you can spray the leaves of your plant.
Plants actually have pores in their leaves called stomata. The stomata are open in the early morning and late evening to allow gas exchange, which is used in photosynthesis.
These stomata also act as a transport system for nutrients. When you spray your compost tea on the plants, the bacteria in the tea acts as a glue and hold onto nutrients for the plant. They will also fill in infected spots on the plant, which helps reduce diseases and keeps your plant healthy.
Fungi will also be present in your compost tea, and fungi compete with disease-causing organisms for food. They can out-compete the bad guys. One study showed that compost tea helped eliminate blossom end rot in tomatoes. This was due to the levels of fungi in the tea which out-competed the disease organisms.
Compost Tea is Not Just For Veggies
Composts tea isn't only beneficial in the garden. Do you have a bare spot in the yard where no grass is growing? Pour some compost tea on the area to rejuvenate it.
Houseplants also greatly benefit from being watered with compost tea. In fact, the low level of nutrients is perfect for houseplants that get all spindly with typical fertilizers. Put some compost in a small cotton tea bag and place it in your watering can. It will be good for several waterings.
I like to break out the compost tea recipe when I am going to transplant trees or berry bushes. They are already stressed from shipping. What better way to give them a nice healthy drink.
What do you do when your compost tea is all gone? Empty the pillowcase and its contents back into the compost pile. The microbes and earthworms will mix it all up and revitalize it.
Having a good compost tea recipe in your arsenal will transform your garden. Not only does it save you money, but you'll notice the difference when your plants are healthier and happier than they would be with conventional fertilizers.