It’s often thought that sandy soil isn’t good for growing much besides root crops and some veggies. But this isn’t the case. One of the things that most people don’t know is sandy soils are surprisingly good for growing grass. The best soil texture makeup for a lawn is 70% sand, 15% clay, and 15% silt.
It is vital to keep in mind that while sandy soils are great for growing grass, their very nature does present some challenges too.
Sand doesn’t retain water well. After it rains or your water your lawn, water moves quickly through the profile and out of the root zone faster than it does with other soil types.
Sand doesn’t have a high cation exchange capacity (CEC), so it doesn’t hold nutrients in the upper soil layer. Since water moves quickly through sandy soils, the nutrients get pushed out of the root zone faster than other soils.
The most important aspect of growing grass in sandy soils is choosing the right type of turf. In this case, the best grasses to grow are drought-resistant. Warm-season grasses tend to be better adapted for drought conditions, but some cool-season grasses have good drought tolerance.
Warm-seasons grasses suitable for sandy soils include:
Bahiagrass (Paspalum notatum).
Bermuda grass (Cynodon dactylon).
Carpetgrass (Axonopus affinis).
Centipedegrass (Eremochloa ophiuroides).
St. Augustine grass (Stenotaphrum secundatum).
Zoysiagrass (Zoysia japonica)
Cool-season grasses include:
Creeping bentgrass (Agrostis palustris).
Fine fescue (Festuca spp.).
Kentucky bluegrass (Poa pratensis).
Tall fescue (Festuca arundinacea)
To help grow vigorous, healthy grass in sandy soil:
Work 2 to 3 inches of organic material (compost, aged manure, peat moss) into the upper 6 inches of soil before seeding new lawns.
Topdress established turf every two to three years to improve organic matter. Adding this material helps increase water retention and nutrient holding capacity. Plus, it adds nutrients to the soil.
When mowing, cut grass at least 3-inches long to encourage deeper root growth.
Mulch grass, leaving the biomass on the lawn instead of bagging the clippings.
Avoid the temptation to water your grass in small amounts frequently. Less frequent soakings encourage roots to grow deeper.
Apply fertilizer at a reduced rate, more often than a typical regime, since nutrients move quickly out of the soil profile.
How To Fertilize Grass Growing In Sandy Soil
Sandy soil presents numerous challenges to fertilization. Due to its coarse, grainy consistency, sand soil dries out quickly and does not hold a lot of nutrients for turf.
Normally, a lawn is treated once monthly with a fertilizer containing nitrogen at a ratio of one pound per one thousand square feet. In a lawn with sandier soil, applications of fertilizer should be done more frequently, usually twice as often, and in smaller quantities. Some people call it “spoon feeding”.
Of course, the amount of fertilizer required does depend on the type of grass planted. Tall fescue for example is well suited for sandy soil and does not require frequent fertilization.
Sometimes better results are achieved when the nitrogen based fertilizer is applied in smaller amounts. This prevents oversaturation of the soil, which would then not be able to absorb all of the nutrients. In turn the excess nitrogen will burn the grass and counter what it was trying to do.
Slow release fertilizers are better than fast because the granules that they are comprised of hold better in the loose sandy soil and are more resistant to washing away. An added benefit is that slow release fertilizers are not water soluble so their state does not change with the weather.
Slow release fertilizers will also continually release nitrogen that would otherwise be washed away with watering or rainfall.
While not typically considered when thinking of fertilizers a good product for sandy soil lawns in compost.
A compost top layer will help the soil hold onto nutrient and water as well as providing additional aeration for a soil type that is typically compact. Organic fertilizers are also good tools in this scenario. While not as fast acting its synthetic counterpart, organic soils tend to be longer lasting. Additionally they are generally less abrasive on the turf and more environmentally friendly.
Unfortunately because of their lack of potency, organic fertilizers need to be applied in large quantities for the same amount of effectiveness. The tradeoff is between fast acting synthetics or longer lasting organics in an application where the root issue is not only lack of nutrients but an inability to retain what nutrients are present.
Organics also contribute more towards soil health than plant growth, which is more often than not the actual problem with the lawn.
