Soil · Houston
Compost-enriched soil vs. topsoil for your lawn and garden
When installing sod, seeding a lawn or building a bed, the first thought is usually to bring in topsoil. Plain topsoil can lack the organic matter a root system needs.
Why plain topsoil falls short
Topsoil by itself often does not retain moisture well and has poor structure. Nutrients leach with rain and irrigation, so roots stay shallow. Topsoil also has no standard definition: fill dirt with clay chunks gets sold under the same name.
Where our topsoil comes from
Screened Sandy Loam Topsoil is straight topsoil, dug out of this property and screened to half-inch minus so the clay and rock come out. It is not blended with anything. We sent a sample to a lab and it came back classified as a sandy loam, and that is where the name comes from.
Sandy loam and loamy sand are two different materials, and the names sit close enough together to cause trouble. The second word is the main component. Loamy sand is sand with a lot of loam in it, and it is the base of Lawn Mix. Sandy loam is more loam than sand, and it is the base of Tree & Shrub Mix.
What compost adds
Compost mixed into a soil improves moisture retention and structure. It stores nutrients for plants to use when they need them, and it carries the trace minerals and organic matter that plain dirt does not.
Casco Compost is made here from wood shavings, animal manure and food waste. The manure is horse manure from area stables and rodeo manure; the food waste is fruit, vegetable, meat and dairy from food waste collection companies. We run it in windrows, move it to static piles to cure, and let it finish before it goes out. We work in small batches, which is what makes that possible: a yard taking in more feedstock than it can hold has to turn piles off the pad to make room, sometimes before they have finished cooking. We are registered with TCEQ under the notification tier.
For beds and new gardens, Garden Mix is Casco Compost, humus and sand, with no topsoil in it. For turf, Lawn Mix is loamy sand, Casco Compost and humus. Both are screened to half-inch minus. Do not use a blend that smells sour or arrives hot, because that compost is still working and will tie up nitrogen.
Mycorrhizae
Compost-enriched soil also encourages mycorrhizae, beneficial fungi that help a plant withstand drought and temperature swings, improve mineral uptake, and assist nitrogen transfer. Fill dirt has little organic matter for that biology to live on.
If a supplier cannot name what is in their topsoil, treat it as fill. Ask what the compost is, how long it was held, and what it smells like.