Does Sandy Loam Promote Grass Growth?

Sandy Loam Texture

• According to the Master Gardeners of Mercer County, sandy loam is defined by its combination of minerals, water, air and organic material. A quality sandy loam consists of 45 percent minerals, 25 percent air, 25 percent water and 5 percent organic material, which provides critical nutrients and texture for water movement into the ground. Active grass growth depends on air pockets throughout the soil as roots absorb oxygen. Earthworms populating your soil also aerate sandy loam as they naturally cultivate the material into usable elements for root absorption.

Roots and Underground Stems

• Whether you grow your grass from seed or sod, sandy loam promotes turf establishment because of its loose consistency. For example, tiny grass seedlings do not have strong root systems to push through clay soil; they may die back if roots cannot pierce the ground for sustenance. In contrast, sandy soil allows for root spread, but the ground cannot hold water long enough for absorption into the grass itself. Hard-packed soil also hinders underground stem, or rhizome, growth. Many grass varieties rely on vegetative spreading for added reproductive success. Underground stems move easily through sandy loam to fill in any bare turf areas that may be otherwise fraught with weeds.

Water Absorption

• In general, your lawn needs infrequent irrigation sessions that dampen the soil to a 6-inch depth -- about 1 to 1-1/2 inches of water a week is typical. If you avoid light sprinklings, your grass roots naturally search downward for moisture in between watering. Sandy loam provides the space and moisture necessary for deep root growth. Your lawn remains strong and stress-free when it can access nutrients, moisture and air deep in the ground. Shallow roots in hard soil locations promote disease and pest infiltration because the grass succumbs to drought and other stresses.

Mowing and Clippings

• If you cut your grass too short, also known as scalping, the turf redirects energy from deep root growth to blade development. Although sandy loam encourages root spread, improper mowing habits negate its benefit as grass develops drought symptoms by dying back. Maintain a 2- to 3-inch grass height and only remove about one-third of the blades' length at a time to encourage root growth in sandy loam. Additionally, allow some of your grass clippings to fall onto the turf as they move into the soil below. As clippings decay, they add nutrients into the sandy loam to continually renew the friable and nutrient-rich soil texture.