Is dolomite or lime effective in controlling sandspur? I’ve heard sandspur won’t grow if we sweeten the soil.
According to UF specialist and Extension agents, attempts to kill sandspur by liming or using dolomite is not effective. These burr were harvested beside a lime rock road.
Additionally, unless a soil analysis calls for it, application of lime could contribute to decline of warm season turf grass. Proper fertilization, irrigation and mowing heights may improve turf grass. Keeping grass healthy and vigorous is one of the best ways to crowd out sandspur.
In summer, dig/hoe/pull up sandspur plants. When mowing, keep burr within the contaminated area. Clean mowing equipment and prevent spreading burr to uncontaminated areas. In fall, drag cloth/carpeting etc. across the area to collect burr. Discard the cloth. This will reduce the seed bank resulting in fewer plants next spring. Easily accomplished in smaller areas, for larger patches, contact the extension office for recommendations.
“On those areas where turf is to be established (including sod and winter overseeded areas), most preemergence herbicides should not be used 2–4 months before planting. Otherwise, root damage and germination reduction of the turf seed may result.” Electronic Data Information Source (EDIS) document ENH884, Revised September 2020.
What good are sandspur?
My friend has a burr infestation. She views it as a beneficial dog deterrent. She says her small dog stays out of that area, which borders a moderately trafficked road. Do you have a similar experience? Please share, I’d love to hear of it.
Plagued by sandspur? Take action before they emerge next spring.
Properly applied, pre-emergence herbicide in effective in controlling sandspur. The pre-emergent product should be in place before the seed germinates. We know air temperature, soil temperature and soil moisture influence germination.
By understanding the life cycle of Southern Sandbur (Cenchrus echinatus) and the Coast or Field Sandspur (C. spinifex) we can better control this grass-like weed. Sandspur is an annual plant. It germinates from seed, grows and produces fruit (the burr) in one growing season.
Pre-emergence herbicide, used according to label recommendations, inhibits growth BEFORE you see above ground leaf. Follow label recommendations to incorporate and activate the product. Control is enhanced with irrigation or rainfall immediately following application. The chemical barrier must present in the soil before the seed comes up. Once leaves are present, a pre-emergent herbicide is not effective on that plant.
Pre-emergence herbicide may be purchased at big box store and garden centers. Follow label recommendations. The following are listed by active ingredient and not brand name. These are safe for use on bahia grass, St. Augustine, centipede and Bermuda grass when used according to the label.
> Benefin + trifluarlin
Since sandspur seed do not germinate at the same time, reapply herbicide in 6-9 weeks. Herbicide may injure or kill ‘innocent bystanders’ such as shrubs and flowers. Therefore, follow label precautions.
I am sure sandspur are here by design. One day we may understand their value. In the meantime, I’ll be digging them out and trying to reduce the spread at the Demonstration Garden, UF/IFAS Extension Levy County, Bronson. Until next time – Spread Joy!