HOME & AG: Sandburs present prickly pickle

Oklahoma in March means buds on trees are turning into leaves, and thistles, weeds and burs are popping out of the ground.

Many in agriculture want to know how to deal with sandburs, not because they are particularly harmful to crops or livestock, but mostly because those who come across them find them annoying.

Sandburs go by different names: sandspur, buffelgrass, sticker grass, cockleburs, or more casually, brambles, briers or nettles. In the grass family, they grow on the top of shoots, and when they are ready to wreak havoc on humanity, they will hitch themselves on socks, pants, flannel, shoelaces, or other articles of clothing, as well as on animals.

While they are not particularly harmful – aside from those who experience severe allergies — they can be a source of inconvenience.

“The sandbur is one of the most troublesome weeds that farmers, ranchers, and landowners have, and it’s not for the usual reasons as with other pasture weeds,” said Bradley Secraw, Cleveland County OSU Extension agriculture educator. “It’s not due to crop competition or low forage quality, but instead, it is due to its painful spines. That’s it!”

He said farmers aren’t the only ones who avoid sandburs. While the grass has excellent forage value in livestock, especially when the grass is young and the sandburs haven’t had a chance yet to form, cattle will avoid it when the sandburs have reached maturity.

For this reason, farmers in Oklahoma are doing what they can to rid their pastures of the prickly plant.

“They can be managed over the long term, but there is no silver bullet, Secraw said. Depending on the situation, management can include soil fertility and cultural and chemical controls.”

March is the time for farmers to launch a comprehensive sandbur control program, which prescribes cultural controls, chemical pesticides and controlled burns, according to the educator.

“Sandburs are native, opportunistic, drought-tolerant grasses that take advantage of disturbance,” he said. “Unfortunately, many of our farming and ranching activities create disturbance including grazing, hay making, tillage, and burning.”

This kind of soil disturbance offers opportunities for airborne sandbur seeds to make themselves new homes.

Secraw said sandburs can take over areas with low fertility and areas where forage grasses are stressed.

“While most common in sandy soils, sandburs will also grow on heavier soils,” he said. “Optimizing soil fertility and forage management will make forage grasses more competitive with sandburs and other weeds.

“This starts with a soil test to check for deficiencies and to create a fertilizer program to improve forage growth.”

Secraw added it is important to prevent overgrazing, as sandburs can’t grow where another plant exists. He shared a story about how his friend mowed a path through a bermudagrass meadow that was relatively free of sandburs.

“Sandburs completely filled that path while the unmowed meadow around it remained comparatively free of sandburs,” he said. “This is not to say that we cannot utilize our fields to control sandburs. It is simply an example of the influence of forage management in controlling them.”

Those who choose to use controlled burns, he pointed out, should use herbicides as well because bermudagrass does not generate the kind of fuel to raise fire temperatures high enough to kill sandbur seeds.

“The fire may actually cause more sandburs to germinate,” Secraw said. “However, this may allow the producer to kill more sandbur at once with herbicide control measures.”