Prickly Pear Cactus

Plant taxonomy classifies prickly pear cactus as Opuntia. The specific type with which I deal below is Eastern prickly pear cactus, which is Opuntia humifusa (synonym: Opuntia compressa).

As I note in my gallery of pictures of cacti and succulents, all cacti, including Opuntia humifusa, are considered "succulents."

Opuntia humifusa grows in clumps reaching 6"-14" tall, with a width of almost twice that. As it matures, it becomes more prostrate in its growth habit. It bears 2"-3" yellow flowers. Depending on where you live, the plant may begin blooming in either summer or late spring. The fruit from which the plant derives its name is also called a tuna (Spanish).

The flat, bluish-green vegetative parts are referred to as nopalitos or "pads." The pads resemble nothing more so than a bunch of spiny beaver tails stuck together. In fact, another species of Opuntia, namely, Opuntia basilaris, is called the "Beavertail."

Indigenous to North America, prickly pear cacti can be grown in planting zones 4-10. Despite its hardiness in cold areas, its appearance suffers in winter, as the pads will shrivel.

Grow prickly pear cactus in well-drained soil. Although it famously bears up to full sun, the plant will tolerate being grown in partial sun.

A popular border plant in some areas, prickly pear cactus is useful for xeriscaping, for plantings along dry creek beds, and in rock gardens, being a drought-resistant plant.

Its thorny spines render it a deer-resistant plant. Along the same lines, it suggests itself as an intriguing possibility for a low, informal hedge plant at the warmer end of its range, where the plant grows more vigorously. But be prepared for complaints from neighbors who let their dogs (or kids!) stray into other people's yards!

The cholla, common in the American Southwest, is a similar plant. The genus name for chollas, Cylindropuntia, bears witness to this similarity. To compare the two desert-dwellers, view my cholla picture.

The yellow flowers of prickly pear cactus are succeeded by (usually) reddish fruits, which, after proper preparation, may be eaten. Opuntia ficus-indica is better known in culinary circles, however, than Opuntia humifusa.

Opuntia is the only cactus genus found widely in the eastern U.S. The fact that it ranges as far north as it does (into zone 4 and Canada) also surprises many people.

Prickly pear cactus can spread and become naturalized, because fallen pads have the ability to root in the ground. You can take advantage of this fact to propagate it vegetatively. Just take cuttings, dry them for a week to let the wound heal, then insert the wounded end into sand, vermiculite or a similar medium. It's easier to start them via cuttings than by seed.

Be careful to handle prickly pear cactus plants only when wearing sturdy gloves and wielding tweezers. In addition to the discomfort you'll experience otherwise, the sharp glochids can cause allergic skin reactions upon contact.

We expect the scientific names of plants to be logical. Occasionally, we are disappointed, as is the case with the first half of Opuntia humifusa. The genus name, Opuntia derives (via the Latin author, Pliny the Elder) from a town in Greece named "Opus," where some spiny plants grew, apparently. But true cacti are native to the New World, making this name something of a misnomer.

The etymology of the species name, humifusa has a more satisfying rationale behind it. Humifusa is composed primarily of two Latin words and translates as "spread over the earth," a reference to the plant's prostrate growth habit.