Super Soil Cannabis Grow Guide: Mix, Cook, Water Only

The short answer

Super soil is a base potting mix loaded with organic amendments, then left to sit and cook for a month or longer. When it's ready, you put a rich layer in the bottom third to half of the container and a mild layer on top where the roots first land. After that you water with plain, pH-adjusted water and let the plant feed itself. It works best with photoperiod plants in 7 to 15 gallon pots, outdoor runs, and growers who would rather not mix bottled nutrients every few days.

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What goes into a super soil mix

Three parts. A base, a humus portion, and aeration.

Super Soil Recipe for High Yield Cannabis: Mix, Cook, Plant

• Base: peat moss or coco coir, about 40 to 50 percent of the volume.
• Humus: worm castings, finished compost, or both, 20 to 30 percent.
• Aeration: perlite, pumice, or rice hulls, 20 to 30 percent.

The amendment list is where recipes split apart. A standard spread looks like this:

super soil vs living soil for cannabis

• Nitrogen: blood meal, alfalfa meal, fish meal.
• Phosphorus: bone meal, bat guano, rock phosphate.
• Potassium: kelp meal, greensand, a small amount of wood ash.
• Calcium and magnesium: dolomite lime, gypsum, oyster shell flour.
• Trace minerals: azomite or glacial rock dust.

Amounts matter more than the roster. A common starting point is one cup of each dry amendment per cubic foot of base mix, cut in half for the hot ones like blood meal and guano. If this is your first batch, run half strength and top dress later. You can always add. You cannot take it back out.

Cooking the mix

Moisten the whole pile to the point where a handful feels like a wrung-out sponge. Cover it, keep it out of direct sun, and turn it once a week. Thirty days is the floor. Sixty is better. A warm pile and a little condensation on the lid mean the microbes are working. The smell should be earthy and sweet. If it turns sour or smells like ammonia, it went anaerobic, so turn it and back off the water.

Layering it in the pot

Fill the bottom third to half of the container with the cooked super soil. Fill the rest with a plain, light base mix, the same recipe without the amendment charge. Start clones and seedlings in a plug of plain mix so the first roots aren't sitting in food. The plant figures it out from there. Roots grow down into the hot layer right around the time the plant starts demanding more, which is the whole trick.

Watering and pH

Plain water, 6.3 to 6.8. No runoff needed in a living soil container, and no flushing unless something went wrong. Water slowly and let it soak. Do not let the pot dry out completely, because dry soil kills the microbial population you spent a month building. A mulch layer of straw or rice hulls on top helps hold moisture and keeps the surface biology happy.

Reusing and reamending

This is the part people miss. Super soil is not single use. Pull the root ball, break up what's left, and reamend at roughly half the original rate. Add fresh castings and aeration to replace what broke down over the run. Then cook it again for a few weeks. Most growers find the second and third runs perform better than the first.

Mistakes that cost people a crop

• Planting a clone straight into the hot layer. It will burn.
• Running a 3 gallon pot. Super soil needs volume to buffer.
• Letting the container go bone dry for days at a time.
• Overwatering in the first two weeks, before roots reach the food.
• Skipping the lime. Peat is acidic and will drift your pH down without a buffer.

Get the ratios close, give it time to cook, size the pot right, and the grow mostly runs itself. That's the appeal.