How can you kill prickly pear cacti?

Answer 1

Scrape the Pears into a big pile and add dry molasses. You will have created one of the best composts. To prevent them from growing back, improve the soil with humate, compost, molasses and organic fertilizers

(make sure you don't break bits off and leave them lying there - they WILL re-grow)

Answer 2

Cactus as ground cover can be controlled or eliminated by changing its basic needs for nutrients, moisture, light, and heat. For example, jungle cactus don't tend to survive as ground cover in the extremes of heavy shade or bright, unmitigated light. Desert cactus don't tend to survive as ground cover in the extremes of absolutely no water or overwatering. Additionally, neither type of cactus handles cold temperatures.

Answer 3

The easiest way to kill a cactus is by overwatering. Some cactus plants grow in hot, humid climates. Examples are the epiphytic cactus plants that grow high up in the rain forest canopy. But ground and pot dwelling cactus plants tend to be adapted to dry, hot climates. They won't be able to survive daily doses of heavy watering.

Answer 4

Acetone should do the trick.