Common myths and uncommon truths about the industry's favorite fella!
Much has been said and shouted from rooftops about the benefits of cocopeat. Born of humble origins as coconut waste and baptized in the waters of environmental correctness, everyone seems to be high-fiving cocopeat. Online horticultural and farmer's groups recommend it to new growers as the new "soil-less soil". Nurseries avidly sell plants in cocopeat filled containers. Houseplant parents happily accept this and continue the Holy Grail of Cocopeat.
IMHO, things are amiss. Time to bust some myths...!
While it's certainly true that cocopeat is a highly porous, relatively sterile medium with the sweet attribute of retaining moisture for plant root availability at later stages, it is also nutritionally deficient. Perhaps I should repeat that. Cocopeat is nutritionally deficient. Contrary to industry claims that it is high in potassium, phosphorus, magnesium, calcium and other micro nutrients - it is not. Cocopeat is actually 75% carbohydrates and 25% lignin (a plant polymer resistant to biodegradation). As you would know, carbs can contribute very little to growth when plants need protein to grow. Also, lignin is great for conducting and retaining water in its fibrous structures, but like any slow-to-biodegrade wood - it has no nutritional value. Other elements in cocopeat, that are essential to plant growth, are present in negligible quantities.
So, what gives? How did all the hullabaloo about cocopeat begin and why does it get repeated ad nauseam by one and all? Here's my theory, folks: Much of the misinformation we see/hear/read about is just plain spill-off from the coconut industry. Stuff has to sell. So nutritional value gets exaggerated to make sales :-) Next come the nurseries, where the main aim, I should remind you, is to sell you plants, not grow them for life. And so, for this limited purpose and time span for turning around stock, cocopeat is a boon - it is sterile (so plant loss is minimal), it is water-retentive (so watering time and money is saved), it is light (so freight/courier costs get reduced), and above all, it is CHEAP. The plot gets murkier...Once you buy your cocopeat based plants, and begin growing them, you're eventually going to encounter droopy leaves and weak stems. So, you'll be back to your favorite nurseries with more business - this time to buy fertilizer, or a replacement plant :-)
Before you think I'm dissing cocopeat completely, some qualifying statements are in order. Cocopeat does have its uses, and here are some of them:
The porosity, water-retentiveness and sterility of this medium make it an excellent choice for seed germination. Don't be misled into thinking that cocopeat is feeding your sapling though. Most seeds carry enough food in themselves for growth through germination and into the first one or two weeks of "saplinghood". During this time, cocopeat does a decent job of being a medium for your seeds to do their thing. However, once your saplings reach true leaf stage, switch up asap, or watch your plants wilt.
Cocopeat's attributes make it a good base medium - one to which you can then add nutrient-rich manure, nitrogen-rich compost and phosphorus-rich bone/fishmeal, for instance, and in so doing, bring solid, organic substance to your potting mix to create hearty food for your plants. Don't be fooled into thinking that cocopeat alone will grow your plants to maturity.
Well, there is no third good reason, much as I may like to please the coconut industry! So, besides its use in germination and as a base medium, that's it for cocopeat :-)
Images above show leaf size and color difference in Monstera Adansonii when grown in cocopeat (market specimen - left pic) and when grown in living soil (own specimen - right pic). Both plants were grown in roughly equal volumes of growing media.
Remember, nothing comes close to living soil - one that is balanced with a range of macro and micro nutrients (particularly those your particular plant needs), and one that is humus-rich with an active population of beneficial micro-organisms. Growing your plants in cocopeat is the equivalent of raising a child on a diet of bread, and then more bread! Sooner or later things will go askew and you, and your child, will be needing help!