Why Put Sand on Grass?

By Janine Soriano, Master of Science in Forestry, government environment researcher

Sand is a type of dirt with coarse to fine particles. Because it has large pore spaces, sandy soil has very fast percolation, therefore, it tends to dry easily. This results in poor mobilization of water-soluble nutrients needed by all plants. Regardless, certain kinds of plants naturally thrive on sandy soils. This is commonly observed in plants living along river coasts and sandy beaches. Examples of such ecologically adapted plants are mangroves and seagrasses. In gardening, sand is as vital as the preferred loamy soil – it has a lot of uses particularly, in managing the turfgrass.

Reasons for its use

Sand is a versatile component in any garden work. In germinating seeds, a sandy media is preferred so that fine roots can penetrate through the soil. Potting mixes sold commercially each contain sand, loam, compost or peat moss. Sand allows the workability of the soil medium for faster root production in most plants. Thanks to their bigger particle size and thus bigger space between particles, the roots can pass through these spaces while loam soil serves as a reservoir of water and nutrients. This is the major reason why pure clay soil is not recommended for rearing plants from seeds and cuttings. When the belowground biomass is increasing, it is expected that shoot growth grows vigorously as well.

The process of filling sand on the lawn is called top dressing. In this technique, lawn owners apply a thin layer of sand for filling holes or low spots in the turf. Topdressing also reduces the accumulation of thatch, the dried-up components of grass, by allowing it to decompose. This method greatly improves turf grade. Because of the larger particles, there can be water seepage issues hence it is best to keep the topdressing layer uniformly spread out. Most experts agree that top dressing covers the existing turfgrass, thus it is not advisable to regularly conduct it. Grass re-establishment might become a problem if lawn dressing is incorrectly done. As a warning, topdressing will not correct the soil texture of the turf. Adding sand into a clay substrate will make them harden like concrete. Do not try to fix lawn problems on your own, else the turf would suffer. Choosing the right dressing mix for your lawn would require site assessment, soil testing, and expert advice.

What kinds to use on lawn

While they have a lot of benefits as discussed above, bear in mind that not all sand is the same. Topdressing sand has a variety of mixes to choose from. For repairing lawn turf uneven surfaces, the type of dressing should have a combination of sand and loam that was obtained from the topsoil. Loam is nutritious that can compensate what is lacking when sand is used alone. The sandy loam dressing mix would improve soft surfaces in clayey and loamy types. Adding compost to sand would also increase aeration and water retention to the lawn turf. If the lawn is in a golf course, they use a special type of sand for bunkers. In contrast to ordinary topdressing sand, those used in bunkers follow strict guidelines to ensure the quality of golf courses including particle size and shape, penetrometer value, crusting, drainage, pH, hardness, and infiltration. These greatly affect the speed and spin of the ball.

Best sand for Bermuda grass

Aside from choosing sand types, selecting the turfgrass species is important as well. Some grass types can thrive in sandy conditions, while others do not. Examples of sand tolerant grass are Bermuda, Fescues, and Bluestem. Among these grasses, Bermuda can tolerate heat and desiccation. Because of the large surface area of its leaf blades, Bermuda grass is a good turf species in hot regions and most especially during dry seasons.

Most lawns require 1 ton of dressing sand to cover about 1,000 square feet. In growing this grass, the particles must be fine in the 1/8” to 1/16” range. If coarser particles are used, you might harm lawn equipment reels. The coarse texture would also prevent the spread of Bermuda grass in succeeding topdressing activities.