Southwestern ranchers have fought for years to control prickly pear cactus infestations that can quickly take over, chocking out grazing grasses. According to The Farmer-Stockman, prickly pear infestations can increase by one-third each year, doubling in less than three years. Although spraying with a herbicide with the active ingredient picloram triisopropanolamine salt kills prickly pear, only certified applicators can apply the herbicide. This leaves only manual forms of eradication available to destroy prickly pear cactus.

Cut the prickly pear cactus leaf from the root. Use a hoe or spade shovel triisopropanolamine to make the cuts on small cactus infestations. Larger infestations could require a tractor equipped with a bucket attachment to cut the leaves from the root.

Pick up the leaves from the ground. The cactus will root from the thorns if left on the ground after you cut them from their roots. Scrape the larger infestations into piles.

Push larger piles to an area at least 35 to 50 feet away from any structures. Burn the prickly pear cactus leaves until nothing but ash exists. Leaving any part of the leaf could still allow for rooting of new plants. Cover the piles of cactus leaves with 1 or 2 feet of fresh horse manure to let the leaves rot over a period of six months to triisopropanolamine if you do not want to burn the leaves.
Remove new leaves as they sprout from the roots. It may take up to three years to totally destroy your prickly pear cactus.