Compost tea, at its simplest, is compost that has been steeped in water, usually between 24-48 hours, creating a liquid compost or tea that is rich in nutrients, microorganisms, and humates.
Because of its liquid form, it can be applied by saturating the soil, or as a foliar spray. Regardless of how you apply it, compost tea benefits include improved plant growth, development, and resiliency to harmful diseases.
In fact, it’s recommended that you apply your compost tea in both manners. This way, it will fight diseases and dangerous pathogens found both above and below ground.
You most likely have a basic idea of nutrients (if not, start here), so let’s take a quick look at microorganisms and humates before we move onto how we create compost tea.
The Benefits of Compost Tea for your Garden
Growers using an organic based nutrient solution probably already know the benefit of compost tea, but it can also play a role for the traditional grower.
Compost tea should not be confused with the nitrogen rich manure tea. Rather, compost tea composed completely of organic matter contains the micronutrients and trace elements lacking in a manure tea.
This makes it a vital component for growers formulating their own organic based nutrient solution.
All growers benefit from a compost tea because it makes an excellent foliar feed AND root drench.
There is no danger of nitrogen burn when using compost tea as a foliar feed. This is because it primarily contains micronutrients that are more readily absorbed by through the leaves.
There are also mechanical compost tea brewers which enable you to make your own compost tea whenever you like.
Compost Tea Microbes / Micro-organisms
They might be naked to the human eye, but microbes are vital to growing large, healthy plants in soil. Microbes love working with plants, so let’s take a quick look at their relationship.
- Microbes decompose organic matter and use the carbon and nutrients found in them for their own growth.
- They will then release excess nutrients that will be readily available for your plants.
- Certain microbes consume dangerous pathogens found in soil. For example, certain protozoa consume pathogenic fungi that are dangerous to plant health.
- Other microbes can degrade agricultural pesticides in soil along with other toxic substances.
- Microbes improve soil structure and improve water retention.
- They are self-sufficient, because they digest each other’s dead bodies. This means you will use less organic material for nutrients.
Most compost tea is brewed with aeration supplies e.g. an air pump that supplies oxygen during the brewing process. Supplying oxygen uniformly throughout the tea will support the development of vital microbes that need oxygen to live.
Compost Tea Humates
Humates are complex substances that we know are needed for plant growth and development. They contain a number of organic acids: fulvic acids and humic acids, and macromolecules like amino acids, amino sugars, and peptides.
Understanding humates in their entirety is difficult even for those that are well-versed in soil growing. So for now, just understand that they are crucial for plant growth and development.
Brewing Your Compost Tea or Pre-Brewed Compost Tea
Many gardeners like brewing their own tea, either with ingredients that they put together or by purchasing a kit. This is a really great way to change the strength and type of tea, but you’ll need some equipment to do it.
If you are on your first grow, you will have enough on your plate and may prefer to stick to pre-brewed teas.
That’s why we offer several top of the line brands with different proprietary blends that work fantastically for promoting stronger root systems and an enhanced immune systems.
Brewing your own compost tea
Whether you want to create small batches of just a few gallons or create a leviathan size brewing operation, at Hydrobuilder we make brewing your own tea simple. All of our brewers are stand-alone with easy to use pumps and drains that keep your work area clean and efficient.
Just throw in your ingredients and walk away.
Let’s take a look at what the brewing process looks like with a more hands-on approach:
- Step 1. Gather your brewing supplies and ingredients - You will need your ingredients (check out our kits that do the work for you), a bucket (preferably 10 gallons), and an air pump.
- Step 2. Fill your bucket with water - If using tap water, let it sit out for a day. This allows the chlorine to evaporate away, as it can kill good microorganisms.
- Step 3. Add a catalyst - Your catalyst is simply a nutrient solution for the microbes, and gets them eating and multiplying.
- Step 4. Steep your compost - You will put your compost in a brewing bag, ball, etc. just like if you were actually making tea - screen/bag size should be close to 400 microns.
- Step 5. Aerating the mixture - You want air to pump up from the bottom and up throughout your brewing mixture. This will get beneficial fungi and bacteria moving and doing their job (air pump and stone will make this easy).
- Step 6. Walk away - The brewing process should last for at least 24 hours. The longer you brew, the more potent your tea. You will want to see foam, as this indicates that the tea is brewing properly.
Creating your own compost tea mixture
Remember, the goal of compost tea is to provide your plants with nutrients, fungal colonies, and beneficial bacteria to create a thriving community. While brewing is a simple process, gathering everything you need won't always be.
It’s entirely up to you whether you want to create your tea from scratch or purchase a kit.
A lot of gardeners purchase kits because there are a lot of ingredients that go into making a rich tea. Unless you’re brewing a lot, it’s simply not cost-effective to buy everything. At its most basic, you will need compost, worm castings, fish meal, kelp, and molasses.
If that seems like a lot, just take a look at all the ingredients a compost tea nutrient solution will come with. You’ll see fish meal, feather meal, bone meal, crustacean meal, alfalfa meal, cottonseed meal, kelp meal, dolomite, gypsum, and we’re going to stop there.
Tea kit solutions will come with different ratios of fungi to bacteria and the food to feed each, and the type of plant you grow will determine what ratio you need.
|Type of Plant||Type of Tea|
|Coniferous Trees||Highly Fungal|
|Deciduous Trees||Moderate Fungi|
|Berries||Balanced Ratio of Fungi and Bacteria|
|Vegetables & Grasses||Moderate Bacteria|
If you cannot find your specific plant above, simply find the type that is the closest to what you are growing. If you’re growing in sandy soil, you will want a heavier ratio of fungi because it will help improve and build soil structure.
This should give you an idea why many go for kits, and that’s why we offer a bunch of differently priced kits, with various mixtures of ingredients so you can start brewing on a budget.
Simple Garden Compost Tea Recipe
For this recipe, you'll need:
- Mother Earth Worm Castings
- Mother Earth Sugar Molasses
- Buried Treasure Liquid Guano
- Mother Earth Meal Mix*
- Down To Earth Fish Hydrolysate (fish powder)
- A compost tea brewer
*NOTE: Choose Grow for the vegetative phase of growth or Bloom for the flowering phase of plant growth.
Add 2.5 Tbsp of Meal Mix in a separate tea bag and brew the compost tea for 12 to 24 hours. Top dress the sludge after the brew process. As always cover with fresh media to keep it moist and out of the light.
Applying Compost Tea
You can apply your tea to either the roots by just regularly watering or as a foliar spray - doing both will improve your plant’s resistance to diseases both above and below ground.
Spray your compost tea on the foliage in the morning or late in the day. This will prevent UV degradation of the compost tea.
For most growers, compost tea will not replace the main nutrients they feed their plants with. Basic tea will not harm your plants with nutrient burn so you can apply your tea freely.
Compost tea is not considered a fertilizer, nor is it considered a fungicide. It simply provides your grow media with additional microbial activity which results in better plant growth and development.
It’s common to see gardeners dilute their tea with water between 1:1 to 1:20, but this is not required. Dilute your tea between 1:2 to 1:10 to use as a foliar spray.
Without aeration, oxygen levels can lower by 300% after just 6 hours. You will need to aerate, agitate, and add more food to the tea to increase shelf life. Aerobic microbes are the most beneficial microbes to have in your tea so aeration is key.