For ecological reasons, coconut mulch has started to replace peat as a natural garden mulch, yet it isn't the best choice for all garden uses. Some of its characteristics may make it more costly and troublesome than it is worth, depending on your mulching needs. Despite drawbacks, coconut mulch is a sustainable resource and there are ways to deal with potential problems.
Forms and Uses
Coconut mulch is made from coconut husk fiber, the thick material that covers the fruit. It's also called coir and comes in chips, shredded or compressed into bricks. If you've used coir pots, you've seen coconut husk's moisture retention properties in action. Coconut disks are preformed to provide weed control and accommodate single-stemmed potted plants. Like loose mulch, they retain moisture in the growing medium. Their pre-formed shape holds them in place in the pot, which overcomes a few of the disadvantages of loose coconut mulch.
Expense and Importing
Peat harvesting can damage fragile bog ecosystems, while coconut fiber offers a sustainable resource, yet coconut husk is a relatively expensive mulch. Depending on your budget and how much mulch you need, coconut mulch may be cost-prohibitive. For some applications, the greater water retention, such as to protect favorite thirsty plants during the summer, may be worth the added expense. Despite being touted as eco-friendly, it's usually imported, so there is environmental impact from the transportation of the product. Local mulch materials such as compost, bark chips or buckwheat hulls offer an alternative to coconut mulch.
Rehydration and Weight
Coconut mulch in compressed bricks is convenient and mess-free to transport. When you add water, the mulch expands, generally to two and half times the brick's volume. This makes it compact for unloading and storing, yet having to rehydrate these mulch blocks is an extra step that adds time to your mulching chores. Coir's light weight can be a drawback in some landscaping and garden applications. If you've watched bark chips blow or float away, you know what you'll see when a wind comes up or if rain or irrigation causes pooling water in coconut husk chips. Shredded coconut mulch is also lightweight.
Remedies and Alternatives
Coconut mulch retains more water than peat, offering an advantage for keeping plants hydrated, and it also works well to insulate roots. Used coconut mulch from hydroponics, if available in your area, may offer a substantial price break compared with buying it new. Installing edging can reduce the risk of coconut mulch floating out of planting beds during watering or rains. Bricks, rocks set close to each other or flexible edging that's taller than the level of the mulch helps corral it. Coconut mulch is sometimes called coco mulch, coco disks or coco mats. Take care not to confuse it with cocoa mulch, which is toxic to dogs.