Coconut coir as a growing media can be purchased in either loose or dried and compressed forms. The loose forms are already hydrated and are usually ready to be added to containers or raised beds for planting. The compressed forms require hydrating. Although the hydration process may be laborious, the dried and compressed blocks are much easier to transport to and inside of the growing location. The blocks are ideal for remote outdoor gardens. In compressed form, the blocks typically take up about 1/5th of the space as commercial peat mixes, and are much lighter in weight. For example a 5KG block of compressed coco coir measures about 10” X 10” X 4” and when expanded yields near 72 liters of high quality growing media. That’s enough to fill nine 2 gallon pots; one block per 1000W HID lamp.
Some coirs have been chemically treated, this is most often the case with loose pre-hydrated varieties versus compressed blocks. The treatment has been done to satisfy the cation exchange capacity (CEC) of the growing media. As a refresher, “cations” are positively charged ions, such as Calcium, Magnesium, Sodium, and Potassium. This means that the growing media will hold these ions in a matrix, releasing them as required by plants. There is one slight drawback to this. Until the cation exchange capacity of the growing media is filled, the growing media may hold positively charged nutrient ions, most notably calcium, in reserve, making them less available to plants. However, the cation exchange capacity (CEC) of the coir media is quickly filled, and actually assists calcium absorption in the crop cycle. To ensure optimum availability of all nutrients, supply additional calcium during the first week of growth or during the hydrating process of the coconut coir. Calcium supplement products are ideal for this. Some nutrients specifically formulated for coco tend to have elevated levels of calcium and magnesium while having lower levels of nitrogen.
