Coco: “What is coco?” The grow medium known as coco, is not actually the pulp inside a coconut, but instead it is a product of the coconut husk. In the process of harvesting the pulp of the coconut for the food market, the husk shavings build up oftentimes in large mounds. For many years there was no sizable market for the husks. Then the agriculture industry discovered it was a great grow medium.
"So if it's so great, why isn't everyone using it?" Coco use gains in momentum every year. However there are a few points to remember with coco, just as there are with any other medium. Coco is a passive form of hydroponics. If it's treated just like soil, your plants will suffer. Therefore, some growers don't want to take the coco "plunge". Some growers though, find coco a near perfect compromise between soil and active hydro (such as DWC, NFT, etc...). Let's take a look at some of the pros and cons of coco.
Advantages:
1. Growth Rate...Coco offers a slight increase in growth rate over most soils. There are many reasons for this. Each reason taken individually do not amount to much, however once they come together, they make a noticeable difference. The first of which is oxygen availability.
a. Coco is a light, fluffy, type of medium. Therefore unless one intentionally pushes down on the coco to compact it, it stays light and fluffy. This fluffiness is useful for our purposes because this tells us that there is air between each particulate, or strand of coco. This air has great significance in the root zone. Roots must have a small amount of oxygen to allow plant processes to continue. The more oxygen to the root zone, the bigger the plants can grow. This is in large part, why DWC (Deep Water Culture) and Aeroponics is so effective. This is a somewhat delicate balance though. If it were simply a "more is better" type of situation, we'd be putting inline fans in our pots. But dry by air by itself, quickly dries and kills roots. So don't get too many wild ideas here.
b. A second reason that coco helps to stimulate growth as a grow medium is the fact that it is a hydro process. With coco, one waters and feeds the plants at the same time until there is a runoff out of the bottom of the pots, usually a 10% minimum. This is often referred to as fertigation. This process of fertigation is a key player in the increased growth typically seen in coco since we fertigate daily. Not weekly, or a couple of times per week, but daily. Some growers have been known to fertigate more than once per day. However once a day is the typical rate. Done daily, it is easier to see that fresh nutes are being “washed” over the roots every 24 hours or so. The roots dry just a bit, and then get washed with nutes all over again. This steady supply of fresh nutes is one of the key elements of faster growth in coco.
c. C.E.C. is another reason for great growth in coco. Cation Exchange Capacity is the ability of a medium to hold and release positively charged ions. In short, coco has a high C.E.C. so it can hold nutrients well, and make them available to plants when the plants need them.
2. Reuse. Coco has the wonderful characteristic of being reusable. It must be rinsed THOROUGHLY in order to release all the nutrients it contains. Remember coco’s high C.E.C.? This is why it is best to flush it with 6-10 times the volume of water to the volume of medium. This will ensure that the coco is returned to it’s original inert state.
Disadvantages:
1. Coco does have a few potential drawbacks, though most find them to be minimal. The first on this list is availability. Most “big box stores” such as *ome Depot, do not stock coco. So that leaves some to have to buy their coco online and suffer shipping charges if they do not have a hydro store close enough to drive to.
2. The runoff that occurs with coco is not always easy to dispose of or fitting in all grow operations. For instance, in a large SOG (Sea of Green), the runoff may not have a way to get to a floor drain, making it a less appealing choice as a medium.
3. Price is sometimes an issue if one is on a strict budget. Coco is typically more expensive than soil. This is usually a small difference, but in some situations this difference may warrant another choice in medium. In conclusion, coco is a strong choice if one wants to move from soil to hydro, but doesn’t want the added equipment costs of active hydro. Weigh your choices well. Research will help one determine the best choice for their particular choice of grow style, environment, and budget.
More to come as time allows…