The prickly pear cactus (Opuntia spp.) offers a sharp reminder that cacti don’t just reside in dry, desert climates. Instead, this cactus has a home in the wet, southeast with some species native to Florida. It is a shrub forming cactus that can reach 3 to 20 ft tall and thrives in open areas along roadsides, pastures, and hayfields. It is covered in 3 in long spines and smaller, petite spines called glochids. While the larger spines are more painful, the smaller spines can cause irritation on contact.
The Problem with Prickly Pear
While this plant produces beautiful yellow to orange flowers and vibrant berries of red or purple in mid to late summer, it is far less appealing from a rancher’s or hay producer’s perspective. Although prickly pear does not form dense canopies that choke out desired forage underneath, the spines can cause infection if they break off into the animal’s skin. Cattle tend to avoid the cactus when grazing; however, as infestations expand this causes a loss in overall grazing area.
For hay producers, prickly pear is a much more serious problem. Since cacti spread through fragmentation, the frequent mowing that occurs in hay fields makes for the perfect opportunity to spread. Then before you know it you have more and more tiny prickly pear cacti throughout your field. There is also the other issue of producing contaminated hay. Feeding hay littered with cacti can be harmful to the animals consuming the forage and can result in further spread of the weed into other areas.
Chemical Control Options
So, you’ve been out scouting, and you notice you have prickly pear popping up in your pastures or fields. What should you do? Recommendations from weed scientists at the University of Florida suggest a couple herbicides that can be utilized including triclopyr ester and fluroxypyr. They recommend that triclopyr based herbicides be spot applied due to expense and sever damage to grass stands surrounding the cacti. It is also advised that either diesel fuel or basal oil be mixed with the herbicide. For broadcast applications, fluroxypyr herbicides applied in either the spring or fall, can provide effective control of prickly pear. They do note; however, that damage from this herbicide is not fast acting, with treated plants persisting for 6-8 months after the application. Aside from chemical methods of control, there is always the tried-and-true method of mechanical removal with a shovel.