A cannabis super soil recipe is a layered organic soil mix that supplies all the nutrients a cannabis plant needs from seed to harvest, requiring only plain water. The core of the recipe is a base soil blended with compost, worm castings, and a measured mix of dry amendments like bone meal, blood meal, kelp meal, and rock phosphate. This guide explains how to build your own super soil step by step.
cannabis super soil mix ingredients
What Is Super Soil?
Super soil is a living organic substrate designed to feed cannabis plants for an entire grow cycle without bottled nutrients. The idea is to create a nutrient-rich bottom layer where roots eventually reach, while the top layer provides a milder environment for seedlings and young clones. Microbes and fungi break down the organic amendments, making them available to the plant as needed.
more on this topic
Why Use a Super Soil Recipe?
- Reduces the need for measuring and mixing liquid fertilizers.
- Encourages a healthy soil food web, which can improve plant resilience.
- Simplifies the grow process, especially for beginners.
- Can lead to a smooth, flavorful final product when done correctly.
The Base Recipe: Core Ingredients
A standard cannabis super soil recipe uses a balanced base of soil, compost, and aeration. Then you add amendments in specific amounts. Here is a reliable starting point for a batch that fills roughly two 7-gallon pots (about 14 gallons total).
Super Soil Recipe for High Yield Cannabis
Base Mix (makes about 14 gallons)
- 6 gallons high-quality potting soil (avoid mixes with slow-release nutrients)
- 4 gallons compost or earthworm castings
- 2 gallons perlite or pumice (for drainage)
- 1 gallon coconut coir or peat moss
Amendment Blend (add to base mix)
- 1 cup blood meal (nitrogen)
- 1 cup bone meal (phosphorus)
- 1 cup kelp meal (potassium and trace minerals)
- 1/2 cup rock phosphate (phosphorus)
- 1/2 cup greensand (potassium and trace minerals)
- 1/2 cup dolomite lime (calcium and magnesium, pH buffer)
- 1/4 cup Epsom salt (magnesium and sulfur)
- 1 cup bat guano (phosphorus, use only in flowering layer)
Adjust quantities based on the size of your batch. Keep the ratios consistent: roughly 1 cup of each major amendment per 10 gallons of base mix.
Step-by-Step Mixing Instructions
- Combine the base ingredients in a large container or on a tarp. Mix thoroughly with a shovel or gloved hands.
- Add the amendment blend a little at a time, mixing well after each addition to avoid hot spots.
- Moisten the mix with dechlorinated water until it feels like a wrung-out sponge, not soaked.
- Transfer the mix to a clean bin or tote with a lid. Leave the lid slightly ajar for airflow.
The Cooking Process
Super soil must "cook" or compost for at least 30 days, though 60 days is better. During this time, microbes break down the amendments and stabilize the nutrient levels. Keep the mix moist and turn it every few days to aerate. A warm spot (around 70-80°F) speeds the process. The soil is ready when it smells earthy and no longer has a strong ammonia or manure odor.
How to Use Super Soil in Containers
Fill the bottom third to half of each pot with your cooked super soil. Top the rest with a plain base mix or a light seed-starting mix. Plant your cannabis directly into the top layer. As roots grow downward, they reach the rich super soil and feed on the available nutrients. Give plain water only, and watch the plant thrive.
Tips for Success
- Start with a smaller batch to test the recipe before committing to a full grow.
- Keep a log of your amendment amounts and plant responses.
- Use a pH meter to check your water source; most super soils buffer pH naturally.
- Do not add extra nutrients unless you see a clear deficiency, as super soil can burn young plants if too strong.
With a well-made cannabis super soil recipe, you can enjoy a low-maintenance, organic grow that focuses on water and good genetics.