Coco coir is an increasingly popular type of hydroponic growing medium — and for good reason. There are a whole host of benefits to growing with coconut coir that you can and should take advantage of if you’re new to hydroponics.
There isn’t a good, comprehensive guide to coconut coir out there… until now. In this guide, you’ll get just about everything you need to know about coco coir: what it is, its pros and cons, and the best brands to use.
What is Coconut Coir?
First, we need to understand what coconut coir actually is.
In the past, when coconuts were harvested for their delicious meat and juice, the coconut husk was considered a waste product.
All of the material from the husk to the inner shell of the coconut was a discard product…until people realized it had many applications in gardening and home products.
Everything in between the shell and the outer coating of the coconut seed is considered coco coir. There are two types of fibers that make up coir — brown and white.
Brown coir comes from mature, ripe coconuts and is a lot stronger, but less flexible. White fibers come from pre-ripe coconuts and are far more flexible, but much less strong.
Almost all of the coconut coir used for hydroponics is brown coir, as it’s processed even more after initial harvesting.
How is Coco Coir Made?
To get coconut coir ready for hydroponic and gardening uses, it needs to go through extensive processing.
First, they need to remove the coir from the coconuts. This is done by soaking the husks in water to loosen and soften them. This is either done in tidal waters or freshwater. If done in tidal waters, the coconut coir will take up a large amount of salt, which will need to be flushed out by the manufacturer at a later stage.
Then, they’re removed from the water bath and dried for over a year. After the drying process, which is quite extensive, the coir is organized into bales. These bales are then chopped and processed into various formats, from chips, to “croutons”, to classic ground coconut coir.
There’s a whole lot more that goes into the process of making coco coir safe and optimal for horticultural use, but we’ll get into that a bit lower in the article.
Pros and Cons to Coconut Coir
There are amazing benefits to using coconut coir in your garden. But just like any other kind of growing media, there are also some downsides to consider before you buy
Benefits of Coco Coir
Good transition from soil gardening: Growing in coco coir feels like growing in soil, because the two media look so similar. You can have a completely hydroponic garden that looks almost the same as a soil garden. The only difference is instead of watering with only water, you’d water your coconut coir garden with nutrient-enriched water.
Retains moisture and provides a good environment: Coco coir is one of the most effective growing media for water retention out there. It can absorb up to 10x its weight in water, meaning the roots of your plants will never get dehydrated. There’s also a lot of growing media for roots to work through, promoting healthy root development.
Environmentally safe: Although I am a fan of using sphagnum peat moss in the garden, there’s no denying the environmental concerns that peat moss poses. Coconut coir doesn’t have the same problems. It can be used more than once unlike peat moss, which breaks down over time. It’s also a repurposed waste product from a renewable resource, unlike the peat bogs where we get our peat moss.
Insect-neutral: Most garden pests do not enjoy settling in coconut coir, making it yet another line of defense in your integrated pest management system for your garden.
Can be less complex than “traditional hydroponics”: If growing hydroponically is new to you, coconut coir is a good first step. You can practice the basics of hydroponic gardening without having to buy or build a hydroponic system and perform all of the maintenance that it requires.
Downsides to Coco Coir
Inert: Coconut coir is inert, meaning that it has no nutrients within it. It may look like soil, but it is not soil. This means you will need to add hydroponic nutrients and control the pH when using coco coir. Growing in soil isn’t too different though, as many gardeners amend their soil constantly throughout the growing season anyways.
May need additional supplementation: You may find your plants short on calcium and magnesium when using coconut coir, so supplementing with “Cal-Mag” may be necessary. Other fertilizers will be necessary as well since coir has low NPK levels.
Needs rehydration: Most coco coir products are shipped in dry, compressed bricks. While this saves on shipping costs, it adds labor to your growing process as you’ll need to rehydrate them before you can use them in the garden. This isn’t too hard though!
Mixes can be expensive: Garden suppliers know that coco coir can be annoying to work with sometimes, so they’ve started to offer coconut coir mixes. This saves a lot of time, but is pretty expensive — and making your own mix isn’t too difficult.
Types of Coco Coir
When you buy a coconut coir product, you’re really buying three types of coconut coir: the fiber, the pith (or coconut peat), or the coco chips.
Together, they provide a powerful growing medium. Apart, they have very specific benefits. Here’s a look at what each of them is.
Coco Pith or Coco Peat
The “peat” of coconut coir, the pith looks like finely ground coconut or peat moss. It’s so small and absorbent that if you were to use coco peat as your only growing medium, you might drown out the roots of your plants.
It must be aged properly to be used as a growing media, as it can let out salts that will kill your plant if you’re not careful. Choosing a coconut coir manufacturer that ages properly is thus crucial for good growing.
Coco Fiber
Coconut fiber adds air pockets into your medium. It’s not very absorbent, which is good because your growing media needs air pockets in order to provide oxygen to the root zone.
Coconut fibers do break down rather quickly though, meaning the air pockets they create will also decrease over time.
Coco Chips
Coconut chips are basically a natural type of expanded clay pellet. They’re just made from plant matter instead of clay!
They are best thought of as a hybrid between coco peat and coco fiber. They’re large enough to create air pockets, but also absorb water so your plants won’t dehydrate completely.
When using coconut coir in the garden, it is vital that you use the right mixture of these three types for the best results.
How to Choose High Quality Coco Coir
The most important factors in high-quality coco coir are how it is harvested, prepared, and processed. Because none of these factors are directly in your control, you have to pick suppliers that follow all of the best practices for coco coir production.
After the coir is separated from the coconuts, it’s stored in piles for a few years. This puts it at risk for pathogens due to the natural pH of coco coir.
Most producers that experience this will chemically sterilize the coir so it’s ready for use in your garden. This has its risks as well — it can prematurely break down the fibers and peat.
What Nutrients Do You Need for Coconut Coir?
Because coconut coir is an inert growing media, you will need to supplement your plants with additional nutrition. Remember — this is still hydroponic growing if you are only using coconut coir.
While many people say you need coco coir-specific nutrients, this isn’t absolutely necessary.