If you have walked barefoot across a thin lawn in Wacissa or Lamont in August, you know the sandspur. Field sandbur and southern sandbur are the two that show up in Big Bend yards, and both mean the same thing: sandy ground, thin turf, and a seed bank that is about to get worse.
Identifying it
Before the burs form, sandbur looks like a slightly flattened, light green grass with a wide, rough leaf blade and a stem that often lies along the ground before turning up. It is easy to mistake for a young crabgrass. The difference shows in July and August when the seed heads come out: a spike of hard, spined burs that dry to tan and detach at a touch. Each bur is one or two seeds with a coat of hooks. They catch on socks, dog fur and mower tires and travel that way, which is why the problem spreads along mowing routes and paths.
Why it is in your lawn
Sandbur is an annual that germinates from seed every spring and needs open ground and light to get going. It does not invade a thick, healthy lawn. It fills gaps. On the sandy ground south of Monticello, where turf thins from drought and low fertility, the gaps are there every year. Fixing the lawn's density is the long-term control; our post on managing sandy soil lawns is where to start.
The real fix: pre-emergent in spring
Because it is an annual from seed, sandbur is stopped the same way crabgrass is: a pre-emergent applied before the seed germinates. Sandbur germinates a little later than crabgrass, as soils warm into the upper 60s, so a spring pre-emergent applied in late February or early March for crabgrass usually catches it too, and a second application in late May extends coverage through the summer germination that sandbur is known for.
Products with prodiamine, dithiopyr or pendimethalin are labeled for it and are safe on established centipede, St. Augustine, Bermuda and Zoysia at label rates. Read the label. Do not apply where you plan to seed or sprig.
Post-emergent options
Once sandbur is up, control gets harder and depends on your grass:
- Young plants before burs form: some post-emergent grass herbicides labeled for the lawn type work while the plant is small. Centipede and St. Augustine have fewer options than Bermuda and Zoysia, and rates matter. Check the label for your specific grass.
- Plants with burs already formed: killing the plant does not remove the seed. The burs are viable. Mow with a bagger to collect as many as you can, and dispose of the clippings rather than composting them.
- Spot treatment: a non-selective herbicide on individual clumps works but leaves a bare spot, which is exactly what next year's sandbur needs. Re-plug or re-sod the spot.
Physical removal
For small infestations, pulling works, because the root system is shallow and the plant is an annual. Pull before burs form. Once burs are on, dragging an old blanket, a piece of carpet, or a section of fleece across the lawn picks up a startling number of them. It is low-tech and it reduces next year's seed bank.
Closing the gaps
Everything above buys time. The permanent fix is a lawn with no open ground for the seed to land in:
- Raise the mowing height to the top of the range for your grass. Shade on the soil surface stops sandbur germination as well as any chemical.
- Water deep and infrequent so the turf roots deep enough to survive the dry spring without thinning.
- Correct potassium and, on centipede, avoid over-fertilizing with nitrogen. A soil test through your county extension office tells you what is short.
- Plug or sprig bare areas in late spring. Our bare spot repair guide covers how.
The dog and the mower
Two things spread sandbur faster than anything else. Dogs carry burs from the back of the property to the front. Mowers carry them from an infested yard to a clean one. If you mow both, do the clean lawn first and blow the deck off before moving. It is one reason we blow our equipment off between properties.
FAQ
Are sandspurs and burweed the same thing?
No. Lawn burweed is a winter broadleaf that stickers in spring. Sandbur is a summer grass that stickers in late summer. They need different timing.
Will fertilizing get rid of them?
Not by itself, and on centipede more nitrogen causes other problems. Density comes from height, water and time.
How long until the lawn is clean?
With pre-emergent two years running and the gaps closed, most lawns are down to a few plants by the third summer.
Can you handle it as part of regular service?
Yes. Timing pre-emergent and keeping the cut high are part of any plan we set up.
If the stickers have taken over and you want a program that actually ends it, get in touch. We work the sandy lawns around Wacissa and Woodville where sandbur is a yearly fight.