Soil Aeration and Compost Top Dressing Your Lawn

by Randy Watson

Much of San Antonio has dense clay soils that begin heavy and may be further compacted from heavy use from play, sports activities and pets. Roots require oxygen to grow and absorb nutrients and water. Compacted soils reduce the amount of air and water within the soil. This results in poor top growth and lawn deterioration. Core aeration is recommended to maintain a healthy lawn and can benefit your lawn by allowing for the increasing water, nutrient and oxygen movement into the soil. From personal experience I can also say that aeration and top dressing with compost kept my lawn much healthier through last summer's drought and a healthy lawn helps choke out the weeds, too.

Now is the time to aerate your lawn. Some lawn or landscape companies will perform the service for a fee. Core aerators may also be rented at many garden or rental centers. An average lawn only takes just about the same amount of time as it does to mow. So, you may be able to share the rental fee and usage with your neighbors. Be sure that the machine has hollow tines or spoons to bring the soil core to the surface.

Following aeration of your lawn, a good top dressing of compost is also recommended. Of course you can hire this work to be done by a local landscaping or lawn maintenance company or you can aerate and compost yourself, too.

Good compost can be purchased in bags from your local garden centers or even Walmart. (It takes 14 bags of compost to equal 1 cubic yard.) You can save a lot of money if you buy in bulk directly from the materials yard to be delivered or if you have a pickup truck you can haul 1 to 3 cubic yards at a time yourself.If you purchase bulk compost or top-dressing it will cost approximately $30 a cubic yard plus  delivery which should be between $50 and $150 depending on the amount ordered and how far you live from the materials yard you have ordered from.

The San Antonio Water System (SAWS) says that a healthy lawn needs less water. Aeration and compost top-dressing of your lawn work together for a healty lawn and to reduce the amount of water needed. SAWS recommends that you top dress your lawn with about 1/2" of compost to your lawn

Top-Dressing Table

Lot Size (in Acres) Lot Size (in Square Feet) Minimum amount of compost or top-dressing
0.06 - 0.11 2,500 - 5,000 1cubic yard
0.12 – 0.18 5,001 - 8,000 2 cubic yards
0.19 – 0.23 8,001 - 10,000 4 cubic yards
0.24 – 0.46 10,001 - 20,000 6 cubic yards
≥0.47 ≥20,001 10 cubic yards

I recommend Jerry at for bulk delivery of soil, materials, rocks, compost or mulch in and around San Antonio.