Mulch Benefits all Gardens in Many Ways

Many Benefits of Mulch in Your Garden

Brian Jervis: Ask A Master Gardener

Tuesday, July 18, 2017

Q: I’ve heard a lot of suggestions about using mulch in my garden. Is it really worth the effort? A.M., Tulsa

A: Mulching garden soil is not only worth the effort, but also for a variety of reasons is probably the most beneficial cultural practice you can engage in to help your plants, vegetables, trees and shrubs achieve their full potential.

First of all, mulch can greatly decrease the amount of time you need to spend weeding your garden, which all of us would agree is a plus. But, in addition to less time weeding, less weeding means less chance of damaging plant roots through cultivation and weed removal.

Mulch also increases water absorption and reduces evaporation of moisture from the soil. With a good layer of mulch, we don’t need to water as often, and the water we use is put to more efficient use. This mulch layer also helps protect our plants from soil-borne diseases by reducing splashing from rain and watering.

Regulation of soil temperature during our hot Oklahoma summers is another valuable reason to add mulch to our gardens. Research has shown that nonmulched garden soil at a depth of 1 inch can vary in temperature by as much as 40 degrees during an average summer day, reaching temperatures of close to 120 degrees. Adding a layer of mulch can reduce that temperature increase by approximately 30 degrees, to a high of about 90 degrees. Reducing these extreme variations in daily soil temperature is beneficial to plant root systems.

Oklahoma soils tend to be low in organic matter, so we recommend organic mulches that can be incorporated into the soil at the close of each gardening season. Examples of organic mulching materials would include bark chips, compost, grass clippings, pine needles, sawdust and straw. Shredded leaves from the previous season’s yard cleanup also make great mulch, and you can’t beat the price.

Mulches such as sawdust or wood shavings have high carbon to nitrogen ratios that can cause them to leach nitrogen from the soil as they decompose. To compensate for this, nitrogen fertilizers should be increased by about one-fourth.

We generally recommend a mulch layer of between 2-4 inches, but the depth of mulch depends on the texture of the mulch you will be using. For example, if you were to use sawdust, peat moss, or cotton seed hulls, an appropriate mulch depth would be 1 inch because these are fairly dense mulches. However, if you were to use straw, hay, or other more coarse materials, you may need 4 to 8 inches for an appropriate mulch cover.

Mulching your garden may take a little effort, but your efforts will be rewarded with a more beautiful, productive and healthy garden.

Garden tips

·        When watering your lawn, ornamentals or vegetables, always do so in the morning, if possible. If watered in the evening, plants will go into the night still being moist. Most disease-causing organisms need moisture, and because they grow best at night, leaving leaves wet in the evening will promote many plant diseases.

·        Bulb onions are ready to harvest when the tops fall over. They should be removed and allowed to dry in a well-ventilated, shaded area. After the tops are completely dry, they may be stored in a cool, dry area.

·        Tall, spindly tomato plants with scarce fruit are usually due to either too much nitrogen fertilizer or too much shade.