13 Pros and Cons of Coconut Coir Mulch

If you’re looking for a fantastic and natural mulch for your garden, look no further than coconut coir. There are several benefits to using it. It also has some cons to consider as well. 

You can find coconut coir in most nurseries or online. Besides its use as a mulch, gardeners use it as a hydroponic growing medium and amendment to your soil. 

Before you start using it as mulch in your garden beds or containers, it’s important to understand its strengths and weaknesses. Below are 13 pros and cons of coconut coir mulch. 

Urban Worm Coco Coir

Urban Worm Coco Coir is a proven, eco-friendly worm bedding and soil amendment made from coconut husks. 2 of our 1.4-lb coco coir bricks is the perfect amount of bedding to start the Urban Worm Bag.

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What Is It?

Coconuts are one of the world’s most popular crops in tropical regions. These tasty and nutritious nuts are usually tossed and forgotten about after people use them. In recent years, businesses have started repurposing them for gardeners. 

Coconut coir comes from used coconut husks that have been broken down over time. The space between the outer coating of the coconut seed and the shell is full of fibers. Producers soak the husks in freshwater or saltwater to loosen the fibers. They then dry them in the tropical sun for over a year, compact them, and distribute them as bricks. 

Besides mulch, gardeners use it as a growing medium for their hydroponic plants or a soil amendment. This natural product is long-lasting and makes soil well-drained and more resistant to some pests and diseases. 

Pro: Moisture Retention

Coconut coir is made of tiny fibers that keep in moisture. It’s so effective that it can retain around 10 times its mass in water. This is better than peat and other types of mulch, including straw and wood chips. 

This is a great thing if you live in dry areas with little rain or humidity in the air. The coir will absorb water and keep the soil moist and insulated. The fibers trap the moisture and slow down evaporation. This is especially beneficial in places such as Southern California and Arizona, where dry summer conditions are the norm. 

Moisture in the mulch will encourage a healthy biome in the soil. You’ll see an abundance of critters like earthworms thriving in your soil. 

Pro: Prevent Soil Erosion

Soil erosion can cause big problems in your garden. It removes nutrients and destroys the protective top layer of the soil, exposing your plant’s roots to the elements. 

Several studies have listed coconut coir as a beneficial tool in controlling erosion compared to other types of mulch. Because of its moisture retention abilities, it will absorb excess water, releasing it into the soil slowly. 

The fibers also trap sediments and anchor them to the ground. Even during heavy rains, the coir will absorb the water and trap moving sediments before they erode.

Con: It Can Contain Chemicals 

Some coco coir is 100% natural such as this one. However, some may contain chemicals used in their treatment. 

Some producers use chemicals to eradicate pathogens and pests. The chemicals could remain in the fibers and leak into your garden after watering. This could cause some serious issues over time, especially if you’re growing edible plants. 

To prevent this, buy your mulch from a reputable source. Choose brands that are all-natural and chemical-free. As a precaution, give your coir a good rinse after rehydrating it. 

Pro: Environmental Sustainability

Coconut coir is made from used coconut husks which would otherwise be thrown away. Instead, people collect used coconut husks and process them in nature. The process of breaking down the fibers takes time but very little energy. 

Other mulch, such as wood chips, require timber and a lot of energy to convert them into small chips. Coconut coir production uses water and the energy of the sun to break down the husks into small strands of fibers. 

Some coir is made from mechanical processes that need fuel to run. It also has to be shipped from overseas. However, compared to some other mulches, its environmental imprint is low. 

Con: Nutrient-Free

Coconut coir contains no measurable nutrients, unlike other mulch such as straw and compost. This isn’t too big of a problem as long as your soil is already healthy. 

If you’re looking to add more nutrients to your soil from a mulch, try using compost instead. It will protect your soil and keep the moisture in while providing valuable minerals. 

Pro: Bug-Deterrent

Insects are generally put off by coconut coir. The material contains lignins which, according to some studies, may be natural insecticides. The fibers are also poor environments for insects to thrive in. 

Try using this environmentally friendly mulch if you have pest infestations. You may see a decrease in pests immediately.  

Pro: Antifungal Properties

Lignins may also be antifungal, which can benefit your garden if it suffers from fungal diseases such as root rot. Try using it in addition to natural fungi-fighting techniques. While there is some debate about whether or not the lignin content in coco coir is significant enough to reduce fungal growth, it doesn’t hurt to add it to your garden.  

Con: It’s More Expensive 

Compared to compost, straw, and other common mulches, coconut coir is quite expensive. You’ll pay significantly more compared to other mulches like wood chips and compost. 

It takes a long time to produce, unlike other mulches. It’s also labor intensive, requiring people to wash and process the husks over a long period. This hikes up the price tag before it reaches your local nursery. 

Finally, there’s the shipping costs. Companies ship it over long distances before it reaches your garden. This increases the price you’ll pay significantly. 

Pro: Neutral pH

Some mulches can contribute acidity to soil, such as pine needles. Coconut coir, on the other hand, has a neutral pH. This is ideal for most plants and good for an all-around vegetable garden. 

It’s also beneficial if you’re looking to add it to the soil after using it as a mulch. With a neutral pH, it won’t affect the pH of your soil and make it easier to balance with other amendments. 

Con: It Can Contain Salt

To break down the fibers in the husks, producers have to soak them in water for long periods. While some producers use fresh water, most use salt water from bays and estuaries. 

Once the sun dries the husks, the salt stays in the fibers. Most producers wash their coir before shipping it as a final product, but there’s no guarantee it’s all removed. 

Because of this, wash your mulch before spreading it in your garden. This will leach out any leftover salt before it leaks into your soil. 

Pro: Long-Lasting Material

After you apply it to your garden, it will probably hold on to its form for several years. It will break down over time, but its fibers are strong and can withstand environmental stresses like sunlight and rain.

This makes it incredibly useful if you want to place it over perennials and forget about it. Use it around trees, shrubs, or fruit trees such as citrus trees and avocados. Eventually, you’ll have to add another layer of fresh mulch, but that may take several years. 

Con: Rehydration is Necessary

Most coconut coir comes in brick form. This makes it easier and more cost-effective to transport but gives you an extra step before using it. 

Before applying it to your garden, you’ll have to soak it in water to rehydrate it. After rehydrating, it will quickly expand. Break it up and use it as a mulch. 

Pro: Multi-Use

Besides being a great mulch, there are many uses for this gardening material. The most common is as a soil amendment. Coconut mulch adds a layer of moisture-retaining fibers that prevent over-saturation. Its neutral pH and anti-microbial properties make it a fantastic addition to your soil. 

Its other use is as a growing medium for hydroponic gardens. It absorbs up to 10 times its weight in water, which the roots can easily access. It also allows great aeration which prevents root rot.