Using coconut in your garden

Part 1 - Turning waste into healthy garden soil.

Usually when we talk about coconuts we focus on whats inside - the meat and water. This post is about the outside, the leftovers, the byproduct of all the coconut noodles sautéed and ice cream devoured at our farm. We are talking about everything husked off and every empty coconut which has been split in half and scraped clean.

Those leftovers pile up outside any true coconut lovers kitchen. That pile represents good honest living. It’s something to be proud of it! But that pile also takes up space, creates a trip hazard and becomes a hangout spot for pests. That pile of empty coconuts is a pain in the ass. Thus the pile is occasionally cleared, usually loaded into a truck bed and tossed off a cliff. Empty coconuts could and should get a second life, they have higher purpose than rotting at the bottom of a gulch.

The husk are recyclable. Each piece of husk is comprised of two parts - pith and coir. Coir are the long strands that run the length of the husk. Very strong, coconut coir used to be turned into rope. Rope so strong that it the international standard for rigging oceanic ships. Today ropes are made from synthetics (plastic) but you’ll still see coir in the form of welcome mats outside almost every front door. Coconut pith is the tiny bits between the coir, it looks like bits of ground up cork. Pith is spongy in texture, it absorbs six times its own weight in water and is added to commercial potting soil mixes, creating a moist fluffy medium plant roots thrive in. Pith holds moisture during drought, offering earthworms, mycelium and roots a favorable environment. This is important in Hawaii. A century of industrial pineapple & sugar farming left the ground at most home virtually void of biomass, a heavy lifeless clay that dries out fast.

So our pile of spent coconuts can be transformed from a problem pile to a solution. When visiting Sri Lanka I toured coconut processing facilities and saw the transformation from leftovers to garden products first hand. I watched huge machines rip, tear, tumble and sort coconut into foothills of piths and truckloads of coir. I vowed to start saving and processing all our spent coconut husks.

Shredding coconut husks into pith and coir is no easy task though. Even the strongest chippers, which can shred 2’ diameter tree trunks clog after processing just a few coconuts. We imported our machine from an Australian company that makes mining equipment. Dealing with customs with such a large motor required some permitting, but we got it here. Though not as efficient as the specialized industrial machines we saw in Sri Lanka it gets the job done. It takes a patient hand to feed the machine at the appropriate rate and we are learning the art of letting the husks decompose just the right amount before shredding them. To sift the pith from coir we use an earthworm tumbler on loan from the Maui Family Farmer Training Network. Its a slow process, but we are a small farm so it suits us.

The final products - homemade pith and coir find many uses on our farm. Pith goes into our garden beds and gets mixed into holes when planting new trees. The results are happy plants which require less water during dry summers. The coir gets used as nesting material for our chickens (they love it). We also line the bottom of pots with coir when transplanting and use it as mulch. Laid down thick enough it is truely weed proof.

Working with coconut coir and pith has been a learning experience. Our machines require a tremendous amount of energy and time for the small amounts we produce. We have a long way to go before this will be a viable option commercially. In part II we will look at how homeowners, gardeners and even farmers can get the benefits without the expense or time investment