How to win the fight against stickers

Adam Russell

Texas A&M AgriLife

Whether you call them stickers or sandburs, a Texas A&M AgriLife Extension Service expert can help you win the war against these prickly little pain dispensers.

Sandburs, also known as grassbur or sandspur, are an annual and/or perennial grass. The sharp, spiny burs are a seed pod that can latch on to passersby for distribution to other locations.

“Weed control is ultimately up to the end-user, but sandburs are one of those weeds that can be a painful reminder that our yards may need some attention,” said Chrissie Segars, Ph.D., AgriLife Extension statewide turfgrass specialist, Dallas. “If you’ve ever been stuck by them or removed them from a child or pet, then you likely want some advice on how to get rid of them.”

Segars said Texas’ wide range of climates makes any specific directions to address sandburs difficult. In some parts of the state sandburs are a summer annual that dies back and returns from seed, while in warmer regions they live as perennials that can overwinter as plants. Therefore, control methods and timing differ based on where the plants are in their life cycle.

“In some parts of the state, folks might use preemergence herbicides that will have no effect on the overwintering plant,” she said. “It might prevent the seeds from emerging, but it won’t get rid of the old plant. There are no herbicide treatments that will be 100% effective every time, but they will reduce the plants and subsequent seeds.”

Pre- and post-emergent applications for sandburs

Segars said there are ways to fight sandburs with herbicides that kill plants after they emerge or prevent plants from emerging from seeds. Timing is critical when applying pre- or post-emergent products. Sandbur seed can begin early germination at a soil temperature of 52 degrees and peak at 72 degrees, she said.

She recommends a split application of preemergence products with active ingredients Dithiopyr, Indaziflam, Oryzalin or Pendimethalin for sandburs because of their long germination period. Apply the product to prevent sandburs from emerging and follow with another application depending on label instructions, soil type and weather.

Unfortunately, most postemergence herbicides available to homeowners at big box stores are not labelled for sandbur, Segars said. There are three selective, post-emergence products that are labeled to address sandburs in turfgrass. Katana, Celsius WG and Image 70 DG are more professional-geared products but can be purchased online. The most homeowner friendly – Image Kills Nutsedge – is available online and in home and garden departments.

“It may be too late for preemergence applications in some parts of the state, but this cooler weather means it may not be too late to affect peak germination,” she said. “The second application will catch those seeds that haven’t started germinating yet.”

Segars said it is important to always follow product labels.

Making turfgrass happy can eliminate stickers

Herbicides are a tricky time- and money-consuming way to fight sandburs. But Segars said one thing all homeowners can and should do to fight sandburs is implement cultural practices, including fertilization, mowing, proper irrigation and cultivation to help turfgrass choke out sandburs.

Sandburs prefer nutrient-deficient soils, so homeowners should start the process by taking a soil sample and add recommended amendments to create proper pH levels for your soil and turfgrass types, then follow with nutrients like potassium, phosphorous and nitrogen.

“Sandburs thrive in poor soils, so you want to improve all nutrients in general with fertilizer,” she said. “Only add phosphorous and potassium according to the soil test and nitrogen according to recommendations for your turfgrass type, use of the area, and management capabilities, because St. Augustine grass and Bermuda grass have different needs. Promoting healthy, dense turfgrass is the best defense against most pest weeds, including sandburs.”

When it comes to irrigation, Segars said most homeowners overdo it. They begin watering too early and too often, which can lead to poor root development, weakens turfgrass, and makes it susceptible to diseases.

AgriLife Extension has an application for computers and smartphones – WaterMyYard – designed to help homeowners in North Texas irrigate their lawns properly based on localized weather data. There are a number of other AgriLife Extension publications and resources available to guide homeowners regarding lawn irrigation.

Another effective cultural practice is mowing your lawn with equipment that catches clippings when weeds are mature, Segars said. Catching and removing clippings reduces the seedbank that could potentially develop next year.

“Catching reproductive structures of mature weeds lowers the population of seed you’ll have to deal with in the future, and not catching the clippings and those seed pods can potentially help them spread to new areas of your lawn,” she said. “These practices should be performed consistently and properly to make your lawn a place where turfgrass thrives and makes it difficult for weeds like sandburs to emerge and multiply.”