Using coconut in your garden.
Updated: Jul 11
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 hangout spot for pests. That pile of empty coconuts is actually a pain in the ass. Thus the pile is occasionally cleared, usually loaded into a truck bed and tossed off an indiscrete cliff. Empty coconuts should get a second life, they have higher purpose than sitting at the bottom of a gultch.
The notorious , unproductive "pile method".
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 coconut. Very strong, coconut coir was once spun into rope so strong it became 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 up to eight times its own weight in water and is added to commercial potting soil mixes, creating a moist fluffy medium roots thrive in. Pith holds moisture during drought, offering earthworms and mycelium a favorable living environment. This is important in Hawaii. A century of industrial pineapple / sugarcane farming has left the ground at most home sites void of biomass, heavy lifeless clay that dries out fast. A pile of spent coconuts can be transformed to a solution for this problem.
When visiting Sri Lanka we toured coconut coir processing facilities and saw the transformation from leftovers to garden products first hand. Huge machines rip, tear, tumble and sort coconut into foothills of piths and boatloads of coir destined to become doormats, mattress stuffing, potting liners and much more. Coir is so valued that entire industries exist to process and distribute it.
Shredding coconut husks into pith and coir is no easy task though. Even the strongest chippers, which can shred large tree trunks can clog after processing just a few tough coconuts. The coconut has evolved to survive long falls onto rocks and to float in the ocean for weeks, it is very tough. We shred ours through a Red Roo MS50 mulcher, though a much smaller machine works too. We are still mastering the art of shredding them. Softening the husk by moistening it & letting it partially decompose prior to processing helps. We then sift out the pith using an earthworm tumbler from the Maui Farmer Network. Its a slow process, but we are a small farm so it suits us.
The final products - homemade pith and coir perform many functions on our farm. Pith is used as a starting material for new seeds, as vermiculture bedding and as a soil amendment in our raised beds. The results are happy plants which require less water during droughts. The coir finds a second life as nesting material for our chickens, lining pots when transplanting and as a mulch that if laid thick enougfh is truly weed proof. Our problem pile of spent coconuts is now seen as an asset in multiple ways.
The extremely high energy input machine method .
But one of the most important lessons we’ve learned about reusing coconut is -
YOU DONT NEED ANY MACHINERY AT ALL!!
Simply burying coconut husks works just as well (if not better) for long term soil fertility. Every time you plant anything in Hawaii add some home processed coconut husk and watch how it benefits your plants. As the dry summer months creep in, it’s great to rest in knowledge that throughout your garden are buried coconut husks, acting like sponges, creating space for soil fauna to thrive despite the dryness above ground.
Example of simple low tech burry method, though we did use a small backhoe to dig hole.
Hope this post inspires you to save your coconut leftovers and experiment with them in your garden.