The Basics of Using Mulch

The Basics of Using Mulch
Using mulch around garden plants, trees and shrubs offers many benefits. Mulch helps protect the plant roots from temperature extremes, retains soil moisture and discourages weed growth. A proper layer of mulch also makes the garden more productive and healthier, while reducing the amount of maintenance required.

Mulches can be organic or inorganic materials. Leaves, bark, straw, crass clippings, compost and shredded garden debris are all examples of organic mulches, while inorganic mulches include stones, plastic chips, recycled tires, pebble and landscape cloth. Because organic mulches are natural materials, they break down over time, adding beneficial nutrients to the soil, and they need replaced more often than inorganic mulches.

Some organic mulches, like wood shaving and sawdust, can pull nitrogen from the soil as they break down. When using these mulches, gardeners need to watch plants for signs of nitrogen deficiency--yellow leaves and weak plants--and feed plants with a high nitrogen fertilizer as needed.

Gardeners can mulch around plants anytime of the year; however, when soil has warmed in the spring is the ideal time to apply a layer of mulch. Applying mulch after rainfall helps the soil retain moisture. Gardeners can add more organic mulch as the older layer decomposes during the growing season. No matter when gardeners set out plants, mulch should always be applied at planting time.

A final layer of much in fall helps protect perennial plant roots from the coming winter season. The amount of mulch to spread around plants depends on the type of mulch used. Mulches made up of small pieces should be spread in a thinner layer than mulches made up of bulkier materials.

Thinner layers of mulch should be spread over heavy soils, like clay, while thicker mulch layers are best for sandy soils. As a rule-of-thumb, a one to four inch layer loose mulch is generally sufficient. Keep in mind that dark-colored mulches absorb heat and warm the soil, more than light-colored mulches. Gardeners should not use dark colored mulches around plants with roots like cool soil.

When placing mulch around plants, leave space around the stem, trunk or crown of plants. Placing mulch right up against plants hinders air circulation and can lead to root, stem or crown rot.