By Andi Anderson
Prickly and persistent weeds like cocklebur and horsenettle are common in Ohio pastures and hayfields. These plants are not just annoying — they can impact forage quality and pose serious risks to livestock.
Cocklebur is a summer annual from the sunflower family. Its large leaves resemble sycamore leaves, and though the flowers are small and green, the plant produces burs that cling to animals. These burs can reduce the value of animal fiber and spread the seeds.
Horsenettle belongs to the tomato family and has leaves and flowers that look similar to tomatoes. However, its sharp spines make it easy to recognize. It produces yellow berry-like fruits that look edible but are toxic. All parts of the plant are poisonous, especially the berries.
Both weeds thrive in full-sun areas with disturbed soils, often near feed and water paths where desirable plants are unable to compete. Grazing animals generally avoid them due to their prickly surfaces, but hay containing dried plant tissue may still cause poisoning.
Problems typically arise when animals lack access to good forage or are fed weedy hay. The amount of toxic plant needed to harm livestock depends on species, age, and health.
Controlling these weeds is difficult. Mowing is not effective because both weeds flower low to the ground. Tillage may stir up more dormant weed seeds.
Herbicides are more reliable. Cocklebur responds well to products like aminopyralid, clopyralid, dicamba, 2,4-D, and glyphosate. Horsenettle is harder to control, but aminopyralid, metsulfuron methyl, triclopyr, and glyphosate show good results.
Planting a summer cover crop such as sorghum-sudangrass can also help by outcompeting the weeds. Using a no-till drill and maintaining soil fertility are key strategies.
For more information, visit the OSU Weed Control Guide or contact your local Extension Office. Early action is vital to prevent weed spread and protect pasture health.
Photo Credit: gettyimages-r-j-seymour
Categories: Ohio, Rural Lifestyle, Farm Safety