Cultivation on coco substrate

Posted by Juan Cervantes

On 17. September 2013

Coco substrate has become a popular medium for growing cannabis. Coco substrate looks very similar to soil but there are very big differences that need to be considered.

Why grow on coco?

Growing with coco has many advantages. It combines the positive properties of soil with those of hydroponics.
It has a certain buffering effect on the PH value, can be used like soil, but in contrast is sterile and free of nutrients and microorganisms. This reduces the risk of pests and fungi. In addition, you always know exactly how much nutrient the plant is absorbing. Coco can store water very well and is still very airy. Coco substrate is particularly suitable for hydroponics, but can also be used in the same way as soil. Another advantage is that Coco substrate can be reused. After growing, the coco substrate must be treated with enzymes (especially for coco) and all root remains should be thoroughly fished out. The enzymes ensure that root remains in the medium are quickly broken down and no mould or similar develops. It is also recommended to fill the bottom of the pot with a layer of expanded clay to further improve aeration and drainage and to avoid waterlogging, as cannabis plants do not like this at all.

In what form can you get Coco substrate?

Coco is available as pressed blocks, slabs and slabs or as an unpressed ready mix.
The blocks, plates or slabs need to be soaked in water and allowed to swell. Ready mixes are ready to use, but also cost about the same as soil.
There are also coco tabs, which are similar to Jiffy peat pots and are good for growing cuttings and seeds.

How do I fertilise Coco substrate?

Coco does not contain any microorganisms that are necessary to make the biological nutrients usable for the plant. Therefore, a mineral or hydro fertiliser must be added to the water every time it is watered.
In the meantime, there are special coco fertilisers from all manufacturers, but you can also use the normal hydro fertilisers. It is very important to use enough water (nutrient solution) with every watering, about 20% of the pot volume should run out of the pots at the bottom. This means that for an 11 l pot, 2-2.5 l should run out of the holes at the bottom.

Every three weeks, the plants should be rinsed with clear water, taking three times the amount of water of the pot volume for rinsing. This prevents salinisation (accumulation of mineral salts) of the soil. If the soil is salinated, the plant is poisoned and can no longer absorb nutrients.

When growing on coco, it is essential to pay attention to the EC and pH values. Unlike soil, coco cannot buffer and the nutrient solution can only be absorbed by the roots under good conditions.