What Is Gorilla Hair Mulch?

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Close-up of gorilla hair mulch
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Gorilla hair mulch conjures up visions of plucking fur from primates then spreading it in garden beds. In actuality, gorilla hair mulch is finely shredded bark from redwood (Metasequoia glyptostroboides ) and Western red cedar (Thuja plicata) trees. When the bark is processed into mulch, it becomes stringy, resembling gorilla hair. Because this mulch decomposes slowly and forms a dense mat over time to prevent weeds, it works well in gardens. Don't use in areas where open flames or burning cigarettes could come into contact with it, because it ignites easily.


Laying down mulch in garden beds is time-consuming, so it makes sense to use a material that will last. Redwood and cedar have long been used to make outdoor furniture because they resist rot. Using them as a mulch is no different and why gorilla hair mulch does not need to be replaced for several years. Because it decomposes slowly, it does not release as much nitrogen into the soil to feed plants as mulches that break down more quickly, so you won't be able to rely on it as a supplemental fertilizer.

Blocks Weeds

Using mulch around trees and plants prevents weeds from sprouting because sunlight cannot reach the seeds in the soil below. The denser the mulch, the less sun that can penetrate and germinate weed seeds. Gorilla hair mulch is fibrous and stringy. As the mulch settles, these "strings" lock to form a dense mat that excludes sunlight, preventing weeds. In a report by Californians for Pesticide Reform, the use of gorilla mulch in a school landscape eliminated the use of herbicides when coupled with hand weeding.

Keeps Soil in Place

Like most mulches, gorilla hair mulch cools the soil and slows moisture evaporation, which promotes healthy plants. Because of its ability to form a tightly locking mat, it stays in place and provides some erosion control on slopes. Soil washing off into creeks and bays becomes a pollutant that muddies waters and smothers organisms fish use for food. Putting down a layer of gorilla mulch 2 to 4 inches deep deters weeds and helps keep soil in place.

Where to Use

Gorilla hair mulch can be used most anywhere you use other mulches, just keep it at least 6 inches from plant stems so it doesn't encourage rot and disease. Because of its flammability, don't use it near entryways or places where it's susceptible to fire. You can buy gorilla hair mulch in chain home improvement stores, but it may be more readily available in areas with many redwood trees, which grow in U.S. Department of Agriculture plant hardiness zones 5 through 10, and Western red cedar trees, which grow in USDA zones 6 to 8.


Diana K. Williams

Diana K. Williams is a certified Master Gardener, has more than a decade of experience as an environmental scientist, and holds a Bachelor of Science degree in biology and environmental studies from the Ohio Northern University. Williams is a winner of Writer’s Digest Magazine's annual writing competition.