Shrubby evergreen foliage and woody stems don’t automatically stir up an image of “cactus,” but we can grow some stunning tropical varieties that produce beautiful flowers and edible fruit, are not terribly fussy, and will impress your plant-loving friends when you tell them they are indeed cactuses.
First off, is it cacti or cactuses? I’m going with cactuses. It’s been a common noun in English for long enough to get a regular plural. (Webster’s New World Dictionary says both are correct.)
Many of us had a cactus as our first houseplant and learned a bit about plant requirements and plant protection in the process. My father bought me one when I was a kid. I got stuck by its spines well enough to realize plants can defend themselves. Dad kept noting how dry the soil looked, so we kept watering it. You know the rest.
However there are cactuses that wouldn’t have minded this excessive watering. Cactuses grow in vastly different conditions, from wet tropics to the driest deserts. Still, when we picture a cactus, chances are it is stout, succulent, appearing leafless, and spiny.
The genus Pereskia does indeed defy our cactus expectations. The species are more like shrubby trees with leafy foliage and long, woody stems. Some are climbers, and generally all retain non-succulent foliage year-round unless they’re exposed to a decent chill. While they don’t necessarily look like cactus, there are other, more minute features, like characteristics of the ovary, that also differentiate them from other cactuses.
But rather than being odd ones out in the cactus family, Pereskia is considered by many botanists to be an ur-cactus that retains features of plants from early on in the evolution of cactuses, before they became the desert plants we think of. That alone is really cool. Incidentally, all cactuses are native to solely the New World with the exception of Rhipsalis baccifera, and no one knows with certainty how that one got across the Atlantic to Africa. Otherwise, euphorbias seem to fill the Old World niches cactuses otherwise would.
Pereskia species — 17 are recognized — are found in northern South America, Central America, and the Caribbean, though their relationships are still being debated and researched by taxonomists.
In some ways, Pereskia do look a bit like roses: thorny, bushy and with rose-like flowers. The common name of at least one reflects that: the wax rose, Pereskia grandifolia. In direct sun, it’ll flush in springtime with clusters of pink, waxy flowers. It can serve well as a focal point in a rock garden, or several together can form a baleful hedge that can reach 5 to 15 feet tall. It’ll take our heavy summer rain as long as the soil drains well, but less water is always better than overwatering.
Pereskia bleo, rose cactus, or sometimes also called wax rose, produces stunning, large, deeply orange flowers that glow like traffic lights, and when fruit sets, you won’t believe your eyes. The fruit is bright yellow, bell-shaped, very waxy, and wonderfully odd looking. P. bleo is proportioned more like a tree and can reach 10-20 feet.
P. aculeata, Barbados gooseberry, is cultivated as an ornamental and for its fruit, but was apparently classified as an invasive in Southern Africa. It is unclear if it’s still a problem there.
Finally, Pereskia portulacifolia is a smaller, rarer shrub, but just look at the hot pink flowers against the emerald green foliage. It’s enough to make you overlook the spines.
Pereskia species at Fairchild are growing within or near the arid plots, so plant accordingly in a well-draining spot.