Common Carpetgrass

What Makes It Different

This is the carpetgrass that exists as a product. It sets viable seed in commercial quantities and its tropical cousin does not, and that single fact controls everything else: you can buy it in a bag, ship it anywhere in the South, and have a usable lawn in about ten weeks. The tropical species has to be dug out of the ground by hand.

It is also the more cold-hardy of the two. Both species keep their growing points right at the soil surface, but common carpetgrass holds through the mid-20s °F, which makes Zone 8b through 10 workable. Zone 7 is listed on paper — expect winter damage most years.

The blade is narrower too, 4 to 8 mm against the tropical’s 8 to 12+. Still coarse for a lawn, just less so.

Who It’s For

• A bayou-edge or river-bottom lot in south Louisiana, coastal Mississippi or the Carolina low country, where the water table is high and the yard stays soft after rain.
• A pine-flatwoods lot with sandy, sour soil in the low 5s that has starved out centipede.
• A ditch bank, retention-basin edge or back third of a property that floods and nobody wants to spend money on.

Not for deep shade under a dense subtropical canopy — that is the tropical carpetgrass page, and only in Zone 9b and warmer. Not for dry ground, salty irrigation water, or a yard that gets played on.

Why There Are No Named Cultivars

Because the market is too small to pay for breeding. There has never been an NTEP evaluation program for the species, and without a trial network no breeder can prove a new selection beats what is already in the field — so the work never happened. Clemson did release one improved selection, ‘Chase’, bred for better density and uniformity. It has left commercial production entirely, no grower keeps certified fields, and every retail bag today is generic common seed. Public breeding for reduced seedheads is developmental, not something you can buy.

Since you cannot choose a variety, read the tag:

• Botanical name. It should say Axonopus fissifolius, or the older synonym Axonopus affinis. A bag that only says “carpet grass” tells you nothing.
• Coated seed usually runs about 90 percent. Raw seed goes up to 98.
• About 85 percent is what the market offers.
• Coated or raw. The clay coating holds moisture and puts birds off, which helps on a rough seedbed. But the clay is part of the bag weight, so a pound of coated seed carries fewer live seeds than a pound of raw. Raw costs more per pound and is worth it on a seedbed you can keep damp.
• Not a bargain mix. Carpetgrass turns up as undisclosed filler in cheap blends. Once it is in a centipede or St. Augustine lawn, no selective herbicide takes it back out.

What It Costs And Where It Comes From

At one pound per 1,000 square feet — two if you are patching a thin stand — a 5,000 square foot lawn is about five pounds of seed. Sod is the exception, not the route: one source, in the Louisiana delta and river parishes, cut to order from naturalized pastures. Outside Louisiana, seed is the only way in.

What Changes In Care

Nothing changes from the type page. Mowing height, the mid-June nitrogen, the inch of water a week and the near-weekly summer mowing to knock seed stalks down all apply as written. Two rules bite harder here only because this is the seeded route: wait until the soil is genuinely warm — about 69 °F at two inches, usually mid-April or later — and keep pre-emergent off for the first full year.

Before You Buy

• “Carpet grass” is a marketing word in the South. Nurseries and sod outlets across Texas and the deep South use it for any thick, carpet-like turf. Suppliers in Corpus Christi and Austin sell St. Augustinegrass under that name; West Texas distributors apply it to hybrid bermudas like Tifway 419 and TifTuf. Ask a local yard for “carpet grass sod” and you will likely be handed a different genus. Buy by botanical name.
• A bag of seed is always the common species. Tropical carpetgrass is not sold as seed anywhere in the country, so dry seed is fissifolius by default — reassuring here, a trap on the shade page.
• Do not co-seed it with centipedegrass. It was historically sold blended as a fast nurse crop, but suppliers have dropped the practice and extension advises against it — you end up with a two-color, two-texture lawn and no selective way to fix it.
• If you are clearing weeds before seeding, read the active-ingredient panel on any non-selective product. A familiar “Roundup” label no longer reliably means the non-selective ingredient — some products under that brand are selective broadleaf blends, and one is rated as damaging to carpetgrass.