Compost tea for cannabis

Compost tea is an effective and natural solution for enhancing organic cannabis cultivation. As growers seek sustainable and organic methods to optimize plant growth, compost tea for cannabis has gained popularity for its numerous benefits. This nutrient-rich liquid fertilizer, created by steeping compost in water, offers a holistic approach to nurturing cannabis plants. 

In this article, we will delve into the world of compost tea for cannabis, exploring its advantages, application techniques, and the optimal mixtures for different growth stages. Whether you’re new to organic growing or are an experienced cultivator, understanding the power of compost tea can elevate your cannabis cultivation practices to new heights. Let’s dive in and uncover the secrets behind this excellent elixir for plant health and vitality.

Using compost tea for cannabis growth

Brewing compost tea for cannabis plants is a different technique than liquid fertilizer. Bottled fertilizer feeds your plant’s system with a concentrated blast of nutrients. Compost teas, on the other hand, offer a much more balanced mix of micro and macronutrients as well as microorganisms.

Compost tea has a couple of different mechanisms to help plants generate more yield. In general, it harnesses the power of beneficial bacteria and fungi naturally found in compost, multiplying their numbers with the help of oxygen and sugars. These microorganisms play a vital role in establishing solid roots. The greater the population of bacteria in your soil, the greater the benefits for your plants.

While compost tea offers numerous benefits, it is essential to consider its potential drawbacks for your cannabis garden. One disadvantage is the inconsistency in how it’s made. The nutrient content of compost tea can vary depending on factors such as the source of the compost and the brewing process. That variability makes it difficult to deliver precise doses of nutrients, which makes for inconsistent plant growth. Additionally, it’s a lot more challenging to create compost tea because it’s labor-intensive and takes time.

Contamination is another risk of brewing your own compost tea. Contaminated tea can damage your soil health and expose your plants to diseases. That’s why growing cannabis with compost tea takes a focused approach with oversight.

Creating compost tea for cannabis

Ingredients for marijuana compost tea

A good compost tea recipe for cannabis requires carefully selected ingredients. Consider including these common ingredients when creating your nutrient-rich compost tea.

CompostUse high-quality compost as the foundation of your tea. Compost should be well-aged, free from chemicals or contaminants, and rich in organic matter. Look for organic compost that includes diverse ingredients, such as plant residues, animal manure, and kitchen scraps.
AmendmentsEnhance the nutrient content of your cannabis plants’ compost tea by adding organic amendments. These include worm castings, bat guano, kelp meal, fish emulsion, and rock dust. Choose amendments that provide a balanced mix of macronutrients (nitrogen, phosphorus, and potassium) and micronutrients.
MolassesAdding molasses to your compost tea provides a food source for beneficial microorganisms. Molasses adds sugars that fuel the growth and reproduction of bacteria and fungi, ensuring a thriving microbial population in the tea.
Aeration AgentsTo promote oxygenation during brewing, include an aeration agent like an air pump. An actively aerated compost tea maintains an aerobic environment, letting beneficial microorganisms thrive.
Ingredients for marijuana compost tea
Compost tea aeration system
All the critical components of a home-made compost tea aeration system

Bacterial vs. fungal compost tea 

When brewing cannabis compost tea, you can focus on cultivating bacterial-dominated or fungal-dominated tea. Each has its benefits; here’s a summary of the two:

Bacterial compost tea

Bacterial-dominant tea is rich in beneficial bacteria that aid nutrient cycling and root development. It promotes vigorous vegetative growth and enhances nutrient uptake. This type of tea is ideal for the early stages of cannabis cultivation when plants require nitrogen for lush foliage and root establishment.

Bacterial compost tea for cannabis
Bacterial compost tea is best suited for cannabis plants in the vegetative stage of the growth cycle

Fungal Compost Tea

Fungal-dominant tea contains diverse beneficial fungi that facilitate nutrient absorption and contribute to soil structure. It supports the flowering and fruiting stages of cannabis growth, providing essential phosphorus and enhancing overall plant health. Fungal tea enhances yield and improves the plant’s resilience to stress.

Fungal compost tea for cannabis
Use a fungal compost tea when your cannabis plants enter the flowering stage of the growth cycle

Experimenting with bacterial and fungal teas throughout the growth cycle can offer a balanced approach and maximize the benefits for your cannabis plants. Keep in mind; bacterial teas tend to have a higher pH and lean towards the alkaline side, while fungal-dominant teas tend to be more acidic. 

It’s important to note that fungal and bacterial compost teas have very different pH levels!

Applying compost tea to plants

When to give compost tea

When and how often you use cannabis compost tea depends on many factors, including the stage of growth, what soil you’re using, and overall plant health. Generally, you will want to apply compost tea for vegging cannabis every week or two while they are actively growing. Once the plant switches to its bloom phase, you will want to slow the frequency of the feeds and change your inputs to reflect nutrients best for flower.  

How to apply compost tea

Days 3 days

Once you’ve made your compost tea, you’ll apply the following steps:

  • Step 1

    Ensure the compost tea is well-brewed, strained, and ready for application.

  • Step 2

    Water your plants with plain water before applying compost tea. This helps prepare the soil and ensures better absorption of the tea.

  • Step 3

    Water your plants with plain water before applying compost tea. This helps prepare the soil and ensures better absorption of the tea.

  • Step 4

    Apply enough compost tea to thoroughly moisten the soil around the plant’s root zone.

  • Step 5

    If necessary, gently stir the compost tea occasionally during application to prevent solids from settling.

  • Step 6

    Monitor your plants after application and observe their response to the compost tea.

Vegetative and flowering stages

You can make and adjust your compost tea to meet the specific needs of your cannabis plants during the vegetative and flowering stages. During the vegetative stage, when plants focus on leaf and stem development, compost tea for vegging cannabis with mixtures high in nitrogen and other essential micronutrients is your best bet. This encourages vigorous vegetative growth, giving plants the necessary nutrients to develop strong and healthy foliage. 

On the other hand, there is compost tea for cannabis flowering. Flowering is when plants shift their energy toward bud production. Compost tea mixtures with a higher phosphorus and potassium content are preferred in this scenario. These nutrients promote flower development, enhance bud formation, and improve yield and quality

When applying compost tea during these respective stages, adjusting the application frequency in response to the plant’s health is crucial. By providing the right cannabis compost tea mixture at each stage, cannabis growers can optimize plant growth, maximize yield potential, and support healthy bud formation.


Compost tea is a great way to help cannabis plants grow healthy. It provides nutrients, protects against diseases and pests, strengthens roots, and increases yields. To use compost tea effectively, use good-quality ingredients, keep it well-aerated while brewing, apply it during active growth, apply it to the soil around the plants, and be watchful of how the plants respond. By following these steps, growers can enjoy the benefits of compost tea and have successful cannabis cultivation.

Try your hand at growing, it’s easy with our free Grow Bible

Final pro tips on using compost tea

Can I use compost tea with synthetic fertilizers?

Yes, but it takes a lot of precision. The point of using compost tea is that it adds beneficial microbes to your plants and helps grow the biosphere in your soil, leading to a happy and healthy soil bed and plant. Synthetic fertilizers utilize a targeted approach with a higher concentration of specific nutrients. Therefore, using them in conjunction with compost tea will help provide an immediate solution to a nutrient deficiency.

Can compost tea burn cannabis plants?

No, compost tea usually does not have enough concentrated nutrients to burn your plants. Even still, some growers dilute their teas with water to make them less concentrated.

How can I tell if my compost tea is good or bad?

Typically, you will find that compost tea smells green and earthy, but if it smells stinky, you’ll know it’s contaminated. It’s not a good idea to bottle and store compost tea for long periods; otherwise, it will be contaminated.

Avatar for Nigel Deez

Nigel Deez

Cannabis Cultivation Expert

Working in America's legal cannabis industry for the past 6 years, Nigel Deez bring various experiences to the table. Startin ... See profile

0 comments on “Compost tea for cannabis”