Worried about sustainability of peat moss – or just can’t find any? Well, you might want to try coconut coir instead (also known as coco coir or coco peat).
So, what is coconut coir used for? Coconut coir is used as a good substitute for peat moss in seed starting mix, potting soil, and succulent/cacti mix. Coconut coir is also used to root plant cuttings without soil. Coconut coir can even serve well as a soilless growing medium for hydroponics, aquaponics, or aeroponics.
Coconut coir is gaining popularity as a stand-in for peat moss. It is used in lots of different soil mix products.
In this article, we’ll talk about what coconut coir is used for. We’ll also answer some common questions about coconut coir, for those who are curious to learn more.
Let’s get started.
Hey – you can get our weekly gardening newsletter here!
Join 1000+ gardeners to get access to news, tips, and information.
Delivered right to your inbox – once per week.
How To Use Coconut Coir (Uses Of Coco Coir)
Coconut coir helps if you want to start new plants – whether from seed or from vegetative cuttings. Coconut coir is versatile and finds uses in both soil-based and soilless growing (such as hydroponics, aquaponics, and aeroponics).
For instance, coconut is used in:
- Seed Starting Mixes
- Potting Soil Mixes
- Succulent Soil Mixes (for ones that like more water)
- Medium For Rooting Plant Cuttings
- Soilless Growing Medium (Hydroponics, Aquaponics, Aeroponics)
Coconut coir in seed starting mix is a very common application, so we’ll begin with that.
Coconut Coir In Seed Starting Mix
Seed starting mix is used for planting seeds (usually indoors, in trays or small containers). It is usually made from a mixture of materials so it holds some water – but not too much.
The reason is that seeds need both air and water to germinate. Too much water and the seeds rot (or “drown” from lack of air). Not enough water and the seeds won’t germinate.
This is why coconut coir is used in seed starting mixes. It does a good job of retaining water without drowning plants – not to mention that it is processed to be sterile (at least when you first buy it).
Below you can find 3 recipes for seed starting mix. All of them use coconut coir (instead of peat moss). There is a lighter one, a medium one, and a denser one. You can experiment with the ingredients to discover what ratio works best for you.
Coco-Perlite: basic mix with just two ingredients; a lighter, less dense mix. (75% coco coir and 25% perlite)
- 3 parts coco coir
- 1 part perlite
Sand-Coco-Perlite: mostly coco coir, with smaller and equal parts perlite & sand; a little denser than the first mix. (75% coco coir, 12.5% perlite, 12.5% sand).
- 6 parts coco coir
- 1 part perlite
- 1 part sand
Compost-Coco-Perlite: put your compost to good use! Just be sure use sterile compost. This mix is a little denser due to the compost. (1/3 compost, 1/3 coco coir, 1/3 perlite)
- 1 part sterilized compost
- 1 part coco coir
- 1 part perlite
*Note that coconut fiber (coco coir) is used here instead of peat moss (you can also mix them – for instance, using half peat moss and half coco coir). Vermiculite is sometimes together with perlite – but remember that vermiculite holds more water than perlite.
Coconut Coir In Potting Soil
Potting soil is used for flowers, vegetables, herbs, and houseplants. Some potting soil mixes make use of coconut coir instead of peat moss (and some use both).
Coconut coir in potting soil prevent over or under watering. New plant parents tend to make both of these mistakes at some point!
Coconut coir helps plants to survive by retaining water (which plants need to survive) or by draining (coco coir drains faster than peat moss – but the nutrients drain away faster too!)
Coconut coir also gets wet more easily and decomposes slower than peat moss.
Your choice of potting soil mix depends on what you want to grow. But no matter what plant you choose, plants need nutrients to grow past the seed/seedling stage.
So, any potting soil mix needs nutrients added. Here is a modified recipe for houseplant soil mix (adapted from Cornell University):
- ½ bushel coconut coir
- ¼ bushel vermiculite
- ¼ bushel perlite
- 8 tbsp. ground dolomitic lime
- 2 tbsp. superphosphate
- 3 tbsp. 10-10-10 fertilizer
- 1 tbsp. iron sulfate
- 1 tbsp. potassium nitrate
For something a little easier to make, Clemson University suggests:
- 2 parts pine bark
- 1 part coconut coir
- 1 part sand
It is a good idea to add liquid fertilizer to the soil on occasion. Your plants will need the nutrients, since this soil mixture has little nutritional value.
If you want a good potting soil mix for succulents or cacti, add more sand than for other recipes. The recipe below is adapted from the University of Florida:
- 2 parts sterilized garden soil
- 1 part coconut coir
- 1 part perlite
- 1 part coarse sand
Sterilized garden soil has been heated to kill weed seeds, fungus, viruses, and bacteria. If you want to sterilize soil, fill a sheet pan or tray with moist garden soil. Then, put the tray in the oven at 250 degrees Fahrenheit.
Use a food thermometer to make sure the soil gets up to 180 degrees Fahrenheit, and cook for 30 minutes.
You can learn more about homemade potting soil (and find other recipes) here.
Coconut Coir To Ensure Drainage For Succulents & Cacti
Succulents and cacti don’t need as much water as other types of plants. It turns out that it is easy to water them too much. This is why we add ingredients like coconut coir (or peat moss) and perlite to seed starting mixes – they help to prevent over watering.
There is a succulent/cacti recipe above, but Iowa State University Extension also has one, which uses 1 part organic material (such as sterilized compost or coconut fiber) mixed with 2 parts mineral material (such as perlite or coarse sand).
Coconut Coir To Root Plant Cuttings
When propagating plants by cuttings, you can use coconut coir as an ingredient in your growing medium to help the new plants get started.
Missouri State University Extension suggests that you can use a 50% perlite and 50% peat moss mixture for propagating plants by cuttings. You can modify the recipe by using 50% perlite and 50% coconut coir instead.
You might have to wet the coconut fiber to provide enough water for the cutting until it establishes a strong root system.
Coconut Coir As A Soilless Growing Medium (For Hydroponics, Aquaponics, & Aeroponics)
Hydroponics, aquaponics, and aeroponics are all ways to grow plants without soil. These methods use a soilless growing medium (such as coconut coir) and nutrients dissolved in water (or a nutrient mist, in the case of aeroponics).
Coconut coir is sterile when your buy it new, so it reduces the chances of seed/seedling pathogens (root rot, damping off, etc.) However, it can hold pathogens if it comes in contact with them in the process of growing plants (e.g. soil, etc.)
Other materials for soilless growing medium include mineral wool, grow stone, and sand.
What Is Coconut Coir Made Of?
Coconut coir is made from the outer husks of coconuts, which come from a tropical tree. This material was normally waste left over after production of coconut milk, coconut oil, etc. – but it has found a use in gardening (as a substitute for peat moss).
Many sources of coconut fiber are contaminated with fungus or high salt content. So, they must be sterilized and rinsed prior to processing and use in gardening or farming.
(As you can probably guess, this means that coconut coir makes a good substrate for growing mushrooms!)
Can Coco Coir Replace Peat Moss?
Coco coir can be used to replace peat moss in various soil mix recipes. Just remember that coco coir does act a little differently than peat moss.
For example, coco coir is easier to get wet than peat moss (peat moss is much more hydrophobic, meaning it is difficult to get it wet once it dries out).
Coco coir has a neutral pH, while peat moss has an acidic pH.
Note: coco coir should be amended with gypsum (calcium sulfate) to address low calcium and sulfur levels.
Also, avoid using more than 50% coco coir in any soil mix, since its breakdown tends to “tie up” nitrogen in soil, making it temporarily unavailable to plants.
Can Coco Coir Be Reused?
Coco coir can be reused, since it breaks down slower than peat moss. However, there are some cautions to note.
First, coco coir can hold salt from fertilizer or soil, which it can then release later. Coco coir can also harbor pests (or their eggs), which can end up on another crop planted in the soil with recycled coco coir.
Coco coir used for growing is no longer guaranteed sterile. So, it might have pathogens (bacteria, viruses, fungi) that can harm plants.
Is Coco Coir Biodegradable?
Coco coir is biodegradable, but it takes a little longer to decompose. Coco coir is made from tough organic fibers, which take more time to break down than peat moss or other organic materials.
In fact, coconut fiber is notoriously resistant to decay and biodegradation. Coconuts are known to end up in the sea, float for a long time to distant shores, and germinate on the coast of a new place.
Can Coco Coir Go Bad?
Coconut does not “go bad” or expire, so to speak. It has very tough organic fibers and is resistant to decomposition, even in salt water.
Eventually though, coco coir will break down when exposed to water, air, bacteria, earthworms, and everything in nature that wants to recycle organic material.
Even so, when coco coir used as a growing medium, it can still become infected with pathogens. The pathogens can then spread to other plants if the coco coir is reused.
Does Coco Coir Have Nutrients?
Pure coco coir by itself is not a good fertilizer (especially if you need a fast-release fertilizer). Although coco coir does have some nutrients, they are not readily available to plants.
However, you could saturate coco coir with nutrients, which could then be released to plants over time. In that case, coco coir would be a sort of slow-release fertilizer delivery method.
Why Is Coco Coir Good For Plants?
Coco coir is good for plants for these reasons:
- Water retention – coco coir can absorb lots of water, helping to alleviate problems with dry soil.
- Aeration – coco coir also has lots of space for air, helping to prevent root rot of established plants or drowning of seeds.
- Sterility – processed coco coir is sterile, containing no salt or pathogens (bacteria, viruses, fungi).
- Durable – coconut fibers are durable, meaning it will take longer to decompose than peat moss (so you can replace it less often).
- Organic – coco coir is organic, meaning it will decompose over time, adding both nutrients and organic material to soil.
- Sustainable – coco coir is sustainable, since we can keep getting more of it from coconut trees (rather than peat moss, which takes a long time to replenish).
Conclusion
Now you know about the uses of coconut coir why it is helpful in the garden. You also know answers to some common questions about coco coir.
I hope you found this article helpful. If so, please share it with someone who can use the information.
To find books, courses, seeds, gardening supplies, and more, check out The Shop at Greenupside!
Hey – you can get our weekly gardening newsletter here!
Join 1000+ gardeners to get access to news, tips, and information.
Delivered right to your inbox – once per week.
If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here. Enjoy!
~Jonathon