Vegetable gardeners make use of organic mulch as a sustainable and smart practice

Identify the best mulch for your vegetable garden goals.

Straw being used as an organic mulch. Photo credit: hardworkinghippy, Flickr.com
Straw being used as an organic mulch. Photo credit: hardworkinghippy, Flickr.com

Observations of nature’s phenomenon can provide helpful insight for home vegetable gardeners looking to create more sustainable systems or incorporate sustainable practices. Picture an oak forest’s floor covering of fallen deciduous leaves or a red pine stand’s blanketed needle floor. Both sources of foliage drop to the ground and provide a protective layer over the soil. Over time it breaks down and adds rich humus and necessary nutrients back to the soil for the forest’s continued growth and succession. Home gardeners can simulate this protective layer in their vegetable gardens with the use of organic mulch.

Use of organic mulch within a vegetable garden is a sustainable practice and a Smart Soils technique. George Bird of Michigan State University’s Department of Entomology states “we need to listen to nature” when selecting a mulch or incorporating a sustainable practice. He suggests home vegetable gardeners “need to have a specific objective for using mulch, need to select the best type of mulch for achieving this objective, and then manage it properly.” He notes that there are many types of mulch and that living mulch may be appropriate in some situations.

Using mulch is a smart practice because it will reduce the amount of water loss from the soil; therefore, not as much irrigation will be needed. Water conservation will be practiced. Mulch also creates more uniform moisture for the plant roots. This uniformity creates a less stressful environment for the plant, allowing it to be more productive; that is juicier, riper tomatoes for you.

Mulch reduces soil erosion and crusting. Water droplets from rain or irrigation on a mulched surface can’t directly hit the soil. This prevents soil particles from spraying and keeps the soil’s structure more intact. Through use of mulch, the soil particles are able to group together or aggregate more. This process increases soil’s air spaces and moisture holding capacity which are necessary to sustain microbial life of fungi and bacteria that aid in the decomposition process of organic material, such as the leaves that fall to a forest’s floor or the mulched leaves you add to your vegetable garden. The decomposition or breakdown of this once living material will add necessary nutrients back to your garden.

Applying at least 3 inches of mulch will decrease the likelihood of weed seeds germinating, so you will have less weeding. A Cornell University study reports that the time required to remove weeds in a mulched areas was reduced by two-thirds. Mulch is also used to protect against temperature extremes, both during winter and the growing season. That same study reported mulched plot’s summer soil temperatures were reduced by 8 to 13 degrees. Soil moisture percentages in mulched plots were approximately twice as high.

So, what organic mulch should a vegetable gardener use? Many are available, including bark chunks, shredded bark, wood chips, cocoa hulls, straw, shredded leaves and pine needles. According to Cornell University’s gardening resources “Mulches for Landscaping,” different mulches provide specific goals for a vegetable gardener. Michigan State University Extension recommends checking out this resource to best match your vegetable garden objectives with an organic mulch.

For more information on a wide variety of Smart Gardening topics, visit the Gardening in Michigan website at www.migarden.msu.edu or contact MSU’s toll-free garden hotline at 1-888-678-3464.

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