As a home gardener, you’re probably aware of the growing popularity of using coco coir as a growing medium. In many cases, it’s replaced the once popular peat which was a common ingredient in potting and seed-raising mixes. I’ve been using coco coir at home for quite a few years now. I use it mainly to make my own seed-raising and propagation mixes.
Now I want to share with you how to grow using coco coir. I’ll also give you a rundown on what it is. Plus, I’ll explain why it’s better to use this product rather than peat.
What Is Coco Coir?
Quite simply, coco coir is a fibrous substance made from coconut husks or shells. It’s a waste product of the coconut industry. In the past, it’s traditionally been used to make things like mats, brushes, baskets and even mattresses.
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Coco coir is a completely renewable resource. This makes it the ideal environmentally friendly alternative to using peat moss. Peat moss is now not recommended due to the degradation of the peat bogs through constant harvesting.
Peat bogs are vitally important ecosystems. It’s important to protect these because they store a massive amount of carbon. If the bogs are destroyed, all that carbon would be released into the atmosphere. This is obviously something that we want to avoid.
Coco coir has the same ability to hold moisture as peat does. If you’ve ever purchased it at a garden centre, you’ll be aware that it commonly comes in brick form. When you add water, the material swells to around four or more times its size. This is because it absorbs the moisture and is able to retain it for quite a long time.
As a bonus, coco coir has a fairly neutral pH of around 5.8 to 6.7. And, it doesn’t really contain any nutrients. This makes it the ideal base for creating your own mixes. You can easily add in the nutrients that your plants will need.
How Is Coco Coir Made?
Once the coconuts are harvested, the outer husks are removed and these are then sent onto coir manufacturers. The husks are softened using either a saltwater bath or freshwater. Of course, for gardening, it’s important to select a fresh water coir that doesn’t contain high levels of salts. But, you’ll find that the coco coir available at nurseries and garden centres will be the freshwater kind.
This softening process is known as retting in the industry. You can learn more about this process by visiting a manufacturer’s website. When the husks are soft enough, the fibre is extracted using a manual process of beating the pulp with wooden mallets or using a machine that has flat beater arms inside steel drums. After this, the fibre is allowed to dry. You might be surprised to learn that this drying process can take up to a year – I certainly was!
After the coir has dried and matured sufficiently, it’s processed into bales or bricks such as the ones you’re probably familiar with. Coco coir can also be processed into chips or even seed starter pellets.
How Can You Buy Coco Coir Products?
As I’ve already mentioned, coco coir is commonly available in dehydrated coco bricks to which you just add water. Once wet the fibre bulks up and is similar to a lightweight growing medium that you can use in a variety of ways. This is commonly referred to as coco peat and it’s interesting to note that this product can hold around 8 to 9 times its own weight in water. Even better is the fact that the peat can also hold up to 22% air which is so very vital for strong root systems.
But, that’s not the only way you can buy coco coir. Some manufacturers use it to make basket liners or even entire coir fabric pots. These can be placed inside nursery plant pots and will help to keep the potting soil moist.
Another product of interest is coco chips which are used as a mulch to keep more moisture around the root zone of your plants. This product is also available in compressed bricks and expands when water is added. Coco coir chips will last much longer than straw mulch, so it’s especially useful for using as a mulch on your veggie and flower beds. In fact, it has a potential life span of up to 4 years. This mulch-type product also makes the perfect growing media for indoor plants such as orchids.
On top of these, you can also find a variety of different growing medium mixes including coco coir with perlite. Coco coir is also popular with hydroponic growers because it’s such a lightweight material but still contains plenty of air pockets even when wet.
Can You Grow Plants Directly In Coco Coir?
While it certainly is possible to grow a whole range of plants directly in coco coir, I prefer to mix it with other ingredients depending on what I’m trying to grow to get the best results. While the medium does hold moisture really well, it can often be difficult to rehydrate once it’s been allowed to dry out. That’s why a coco coir mix made with other ingredients is a much better way to use this product.
Plus, coco coir doesn’t contain any nutrients so you will need to add these according to each plant’s needs. Here are some of the ways that I use coco coir.
To Create My Own Seed-Raising Mix
To germinate effectively, seeds need consistent moisture and a nice loose mix so the shoots can easily break through the surface and the roots can grow strongly. For a fairly effective seed-raising mix, I like to blend equal parts of coco coir and either perlite or vermiculite.
Vermiculite is particularly useful because it contains a small amount of magnesium and potassium. Plus, it helps to retain moisture as well.
However, when using this blend to germinate seeds, you’ll need to either provide the young seedlings with some liquid feed as soon as the cotyledons or seed leaves are present and before the true leaves start to grow.
Each seed only contains enough nutrients for the cotyledons and initial roots to start growing. Then, the new roots have to obtain further nutrients for growth from the mix the plants are growing in.
To Create My Own Propagation Mix
I used to work as a professional propagator many years ago and still like to dabble a little by propagating new plants from some of the ones I have growing in my garden. While it is possible to just use regular potting mix for propagating cuttings, I generally prefer to make a dedicated propagation mix by combining equal parts of coco coir, sand and perlite or vermiculite.
In fact, a coco coir and perlite mix creates a nice growth medium that roots can easily grow into. The mix is also great at retaining moisture if you’re using a plant cloche to create a humid environment that is necessary for many different types of plants. When using this mix coupled with a plant cloche, I find that there’s enough moisture so that I only have to add extra water every couple of weeks.
To Extend My Potting Mixes
The product that I buy in compressed coco coir bricks is relatively inexpensive when compared to premium potting mixes, so I like to make some up and mix it with the potting mix. This extends the mix and means that I can fill more pots with it. It’s also quite lightweight so the pots aren’t that heavy to move around, especially when I use large ones.
If you’re going to give this a try, I would also suggest adding some additional slow-release fertiliser granules to give the plants some extra nutrition as they start to grow.
To Add To My Homemade Compost
I have two compost bins on the go all the time, so I always have plenty of nutrient dense compost to add to my garden beds. While I could use this as a potting mix on its own, it’s a little heavier than I would like so I mix it with coco coir to lighten it up.
This is a great way to make your own inexpensive potting mix. While the compost is free, the coco coir is pretty cheap to buy. These are just a few ways that I like to use coco coir in my own garden. So, let’s take a closer look at all the advantages of using coco coir.
What Are The Major Advantages Of Using Coco Coir?
Using coco coir in your garden comes with many different advantages. Here are some of the benefits of coco coir.
Improves Hydration And Water Retention
As I’ve already mentioned, coco coir can absorb a lot of water and hold onto this for quite some time. You just need to ensure that you don’t allow it to dry out completely. This is because it’s not that easy to rehydrate once you’ve filled pots with it. But, if you’re mixing it with other materials, rewetting it does become easier.
If you do happen to have a pot plant that’s dried out, you might find that the water won’t penetrate the mix. The best thing to do is submerge the pot in water until the surface of the mix is damp. The mix uses capillary action to draw the water upwards and fully hydrate again.
Improves Drainage And Soil Aeration
Although coco coir can absorb a lot of water, it does drain freely thanks to air pockets within the mix. This means you’ll have the benefit of a moist mix but one that also has pockets for the air that plant roots need to survive. You can even add it to the soil in your garden as it makes an excellent soil amendment.
The Neutral pH Levels Makes It Useful For A Whole Range Of Plants
The pH range of coco coir is somewhere between 5.8 to 6.7 which means that it’s fairly neutral. This is ideal for a whole range of different plants that gardeners tend to grow in pots. A neutral pH is also much easier to adjust if you need a mix that’s more acidic or alkaline.
Coco Coir Is Reusable
Coco coir is slow to break down and degrade. This means that you can use it over and over again. I often just empty pots into a wheelbarrow or my garden cart and just add some new coir, potting mix or compost and then use it again. This eliminates waste and is the ultimate in recycling.
Coco Coir Is Sustainable And Renewable
As a by-product of the coconut industry, coco coir or coco fibre is an infinitely renewable resource as long as we keep harvesting and processing coconuts. Plus, it eliminates the wastage of the husks and fibre which would otherwise have ended up in landfill. That’s definitely a win for the environment.
Coco Coir Is Clean
Unlike other potting mediums that may need to be sterilised in order to eliminate any fungal spores or bacteria, coco coir doesn’t have these issues. You see, coconut coir contains around 46% lignin, 43% cellulose, 3% pectin and around 5% water. By looking at this, you can probably understand why it has the ability to hold moisture but still contains plenty of air pockets for good drainage.
Put in simple terms, lignin is an organic polymer present in the cell walls of a lot of plants. This gives plants their woodiness and makes them sturdy. When used as a growing medium for healthy plants, this lignin improves microbial activity around the plant roots. It also helps roots to absorb nutrients, among other things.
Useful For Hydroponic Setups
You can use coco coir as a grow medium if you’re setting up your own hydroponic system. This is particularly useful for a system that uses a nutrient solution. This should provide your plants with the goodness that they need to grow successfully.
Are There Any Disadvantages To Using Coco Coir?
While coco coir is a very useful growth medium, there are a few things you need to be aware of if you decide to use it for your plants.
Coco Coir Has No Nutritional Value
It’s important to remember that coco coir doesn’t naturally contain any nutrients. Therefore, it’s far better to mix it with other materials. This will provide your young plants with the optimum growing conditions that they need. At the very least, if you choose to use it on its own, you’ll need to feed your plants regularly to encourage healthy growth.
Choosing The Highest Quality Is Important
When using coco coir as a growing medium, it’s important to read the label. Make sure that the brand you select hasn’t been soaked in salt water as this will not be good for your plants.
The coco coir needs to be rinsed thoroughly in clean water before you grow anything in it. You also want to ensure that the brand you select hasn’t been treated with chemicals.
You Have To Store The Coconut Coir Correctly
If you purchase coconut in larger quantities than you need at any one time, make sure that you store the excess in a dry spot and in a container that has a lid. This will keep it dry until you’re ready to use it again and will prevent fungal growth. It will also stop insects from getting into and damaging the coir.
Frequently Asked Questions
Like every other organic material, coco coir or coconut fiber will eventually break down but how quickly this happens will depend on the quality of the coir and how you store it. As a general rule, it should last for up to four years before it breaks down completely.
If you’re just using small pots and haven’t added anything else to the coir, you might have to water once a day. That’s why it’s really useful to mix the coir with other materials like vermiculite or perlite to help with water retention.
Essentially, one kilo of coco coir will make up to around 15 litres of growing medium if you add around two to three litres of water to it.
To provide the best soil structure for growing carrots, it’s a good idea to mix the coco coir with equal parts of sand and compost. This will create a free-draining mix with plenty of air and water pockets as well as the necessary nutrients that your carrots need for optimum growth.
Final Thoughts
Many seasoned gardeners, myself included, have successfully made the switch from using peat or peat-based mixes to using coco coir as a growing medium or to make our own seed raising blends or propagation mixes.
This product is both sustainable and environmentally-friendly. It has a myriad of uses in the garden, as well as being highly affordable and excellent value for money.
