Even the indoor home cannabis gardener can take advantage of the benefits of no-till gardening. You can grow flavorful, potent organic buds in rich soil that can be reused season after season if cared for properly, without the expense of bagged soil or bottled nutrients.
The concept of no-till gardening is simple, in theory. And in the case of cannabis-container growing, also simple in practice. Reusing a container of soil without tilling it or mixing it between uses allows the gardener to take full advantage of the beneficial fungi, microbes or even worms. Tilling the soil has a particularly severe impact on the beneficial fungi called mycorrhiza that live in symbiosis with plant roots.
Normal container cultivation practices recommend gardeners not reuse the soil in a pot once harvest is over. A grow cycle in a typical potting soil in a bag from a garden center will leave it nutrient depleted and compacted. Often made with a base of peat moss and composted tree bark, most potting soils don’t actually contain any humus. Without any humus, the “soil” needs frequent feeding for minerals, phosphorus and nitrogen.
To get ready for your no-till container garden, you might want to start composting. Some methods of vermicomposting (a technique which uses worms to create compost) are simple and take up very little space, making them perfect for a small-scale gardener. Worms eat almost anything and generate compost in less time than standard composting.
The following soil recipe calls for compost or worm castings. If you start vermicomposting a month and a half before you plan on mixing your soil, you can use this compost instead of buying bagged compost and worm castings. You may be able to purchase decent quality compost and worm castings at a store, but with a little planning, making your own vermicompost is much cheaper.
Depending on how tall you want your plants to be, use three- to five-gallon pots. If you live in a warm climate and you have a balcony, you could even go for 10- or 20-gallon pots, if you want to really go big. Pick a pot that has good drainage. To prevent excessive soil losses through the bottom of the container, some gardeners place a layer of mesh plastic fabric, such as a shade cloth, at the bottom to block large soil particles from flowing out the bottom. Make sure water can still easily pass through the plastic.
First, mix one part pre-soaked coir peat and one part vermiculite. Next, add two parts compost, one half-part worm castings and a slow release fertilizer such as chicken manure pellets. You can also add seaweed extracts and plant mineral feed.
Water the soil and watch it drain. Cannabis needs soil that can dry out almost completely between watering. If you notice poor drainage, add more vermiculite or coarse river sand. Water it again after 24 hours and test the pH of the runoff; it should be between 6 and 7. If it’s too high, add a very small amount of sulfur or sulfur-coated urea. Alternatively, you can add more compost until the pH slowly drifts down on its own. If the pH reads too low, add dolomite lime. After using an additive, water it again and re-test 24 hours later.
Beneficial microbes should start to grow almost immediately. If you don’t plan on adding fresh compost or vermicompost, you may want to consider inoculating with bottled bacteria inoculant or mycorrhizae to ensure healthy colony of microbes. For optimum mycorrhizae symbiosis, dip the root of a clone or seed in packaged spores.
You can start your young cannabis plant in a smaller container as long as you use an organic soil. This will facilitate harvesting because you can easily dig up the root ball to reuse the rest of the soil. On the other hand, by starting your plant as a seedling right in the final pot, you ensure its root structure expands through the entire container to take advantage of everything it can get.
After you cannabis plant has grown past a few inches, throw down some white clover seeds. The clover will simply grow around your plant, acting as a groundcover to prevent moisture loss. In addition, clover fertilizes the soil for you by fixating nitrogen. If you don’t plant clover, make sure to put down some kind of groundcover, like mulch or hay.
Most of the nutrients your plant needs will come from the small amounts of compost you add regularly. Adding too much compost might cause a slight pH swing down, so always be cautious and measure the pH of the runoff. Bacteria and fungus further decompose the compost and deliver its nutrients directly to the plant roots. If you think there’s a nutrient deficiency, add some more chicken manure pellets or organic, powdered mineral nutrients.
Every week, add two tablespoons of molasses to every gallon of water you use. The sugar helps stabilize the population of beneficial microbes. Adding liquid kelp or seaweed extract also helps the beneficial bugs, but you won’t need this boost if you continuously add the runoff liquid from your vermicompost.
Once harvest comes, simply cut the plant as close to the base of the trunk as possible, and dig up the biggest part of the root ball. Shake off any chunks of soil into the pot and compost the root mass, stems and clippings. Any old roots in the rest of the soil will simply decompose. Add some compost and place the next rooted clone directly into the same spot where the previous plant was. Add another generous layer of compost to the entire pot, and then some more mulch, hay, and/or clover seeds.
Using these no-till gardening techniques you’ll notice explosive, healthy growth and rich flavors. By composting kitchen waste and adding it to your soil, you can completely avoid using expensive bottled nutrients and bagged potting soil.
Don’t miss our previous Grow Hack: Simple Trick for DIY Composting