A hardy few deserve space in rock gardens everywhere
by CARLO BALISTRIERI
TOO MANY YEARS AGO TO COUNT, a creative writing teacher plunked a cactus on a round table in front of a group of high school juniors with plenty of other things on their minds. She demanded that we put down our pencils and pens for five minutes, and just contemplate it. The idea was that by concentrating we would see the plant as something more than it actually was—an ordinary cactus—and be inspired to write creatively about the experience.
I don’t remember exactly what I wrote, but the cactus made a serious impression. The little pincushion was truly fascinating, and it strikes me now that gardeners—even gardeners far from the Southwest—ought to take another, closer look at this incredible plant family, the Cactaceae. Like me, they may well be surprised.
Most people regard cacti as tender plants requiring indoor or glasshouse culture. This misconception overlooks the fact that cacti will grow naturally outdoors in all but two or three states, and can be found from the wilds of Patagonia clear to the Arctic Circle. Even in the climatically challenged Northeast, where I garden, a goodly selection of plants is available to the gardener. Cold winters and a generally moist climate pose no problem to many cacti, especially those native to the mountainous regions of North America. All they ask is that you give some thought to their particular needs.
Vigorous, strong-blooming cacti demand full sun—at least five or six hours a day of direct exposure to light. Siting cacti to provide them this many hours is particularly important in northern regions where the intensity of the sunlight simply cannot match that found in their native habitats.
Fertilizing cacti is simplicity itself, because in most cases you don’t have to. Feeding is necessary only if your soil is extremely gravelly, your cacti potted, or your planting an old one, with plants growing in the same place for years. In such cases it may be beneficial to apply a light feeding of balanced fertilizer or well-aged compost in the spring, and again in early summer. Under no circumstances should cacti be fed in late summer or fall. This only encourages a flush of soft growth that won’t have time to harden off before winter comes.
Do not be fooled into thinking that cacti require nothing more than an occasional drip or two of water. All succulents, including cacti, have evolved incredible water-storing abilities, but they must have water to store. Although they can withstand occasional short-term drought, cacti need a regular supply of water, especially during times of active growth. In my experience, rain supplies all the moisture my plants need. Supplemental watering can be reserved for young plants and new acquisitions, or limited to any periods where several weeks go by without a drop of precipitation. Do not water outdoor cacti from October through March.
Far and away the most important factor for success with cacti, regardless of the climate, is drainage. More cacti die in spring because of wet conditions and freeze-and-thaw cycles than from the cold of winter. The most effective way to prevent this from happening is to provide perfect drainage. If your soil is naturally sandy or gravelly, you’re in luck. Many homeowners have a hard-to-handle dry area—for example, a spot along the southern side of the house where overhangs and soffits prevent most of the rain that falls from ever making it to the ground. Such locations are natural spaces for planting cacti and other succulents. The soil stays relatively dry, and the warmth and sun of the southern exposure will support the plants.
Those of us possessing less than ideal conditions will have to work a bit to create our own slice of cactus heaven. The easiest way is to construct raised beds, mixing the soil in the bed with coarse sand or fine gravel to improve drainage. Another solution is to make sand beds, which in their simplest form are piles of coarse sand amended with 10 to 15 percent aged compost. Either type of bed benefits aesthetically and culturally from the addition of a strategically placed rock or two and an inch or two of gravel mulch. Cacti look great close to rocks, and the gravel mulch helps to keep moisture away from the base of the plant, where it can cause rot.
SOME GOOD CHOICES
Cacti for northern gardens can be a couple of inches tall, the height of a full-grown man, or any size in between. Growth forms include balls, flattened pads that look like beavers’ tails, and jointed branches resembling strings of sausages. Cactus flowers are among the most elegant in the garden, with petals that often have a satin shimmer. Their colors range from white, yellow, and green through orange, salmon, red, and purple. Although individual cactus flowers are usually short-lived, a succession of buds ensures that a vigorous plant will be in flower for up to several weeks. And even when not flowering, the forms of the plants and their spines provide architectural interest.
While many cacti will adapt to life in colder climates, six in particular seem to manage especially well. All are hardy to at least USDA Zone 5. Escobaria vivipara (Coryphantha vivipara; beehive cactus) is a small, clumping, ball-form cactus with individual heads about three inches tall. Bright pink flowers, often appearing several at a time, top the stems. One of the first to bloom, its display may continue for two or three weeks. It has a tendency to vanish—its small size and camouflaging spines may cause it to be overlooked when it’s not in flower. Plant it in the open, close to where it will be viewed, or in a container where it can be admired all season long.
Echinocereus reichenbachii subsp. baileyi (lace cactus) produces some of the most stunning flowers of all hardy cacti. Three inches wide, their purply pink petals have a high-gloss sheen and surround a ring of bright yellow stamens and a bull’s-eye of bright green stigmas. The blooms are large enough to cover the top of the plant entirely, completely obscuring it from overhead view.
Join the Cactus Club
It doesn’t matter whether you’re most likely to have desert sand, sea sand, or snow in your shoes-if these plants fascinate you. as it’s their nature to do, the Cactus and Succulent Society of America (CSSA) will be glad to have you as a member.
Founded in Pasadena. California, in 1929, the CSSA now counts nearly 100 affiliate clubs in most states and worldwide. Local chapters offer a chance for even the chilliest cactophile to share plants and knowledge. And every other year, the CSSA national convention draws members from around the globe.
Membership includes a subscription to three publications, access to the CSSA seed bank, and more. So if you have a cactus ranch, a rock garden, or a few succulents on a sunny windowsill, look into CSSA membership. It will bring the care and cultivation of cacti and other succulents into very sharp focus.-Eds.
Cactus and Succulent Society of America P. O. Box 2615, Parhump, NV 89041-2615 www.cssainc.org
Another echinocereus, E. triglochidiatus (claret cup hedgehog cactus), is another early bloomer, with bright red, funnel-shaped flowers. Small pink berries in summer extend its season of interest, while its chunky, corrugated body makes it attractive year-round. Claret cup hedgehog cactus does particularly well planted in crevices between rocks, the way it grows in its native haunts, the mountains of the American Southwest.
Opuntia humifusa (prickly pear cactus) is probably everyone’s idea of a typical hardy cactus. It has the virtue of being an eastern native wildflower. Rangy, but beautiful when in bloom, its glowing yellow flowers perch at the ends of paddle-shaped growth sections. Prickly pear is scantily spined, but has plenty of glochids—tiny, soft, bristlelike spines that tend to lodge themselves everywhere (especially in your knuckles) and can only be felt, not seen. Perhaps the most adaptable of all hardy cacti, O. humifusa can grow nearly anywhere there is sun and well-drained soil. Though its pads will shrivel up and look dead in the winter, they will plump again in spring.
Opuntia phaeacantha (purple-fruited prickly pear) is a great bloomer in good sun, with flowers that range in color from yellow through orange and salmon to red. Like most paddle-forming opuntias, O. phaeacantha grows easily and will develop into a sizable plant over the course of time. Clumps can reach 35 inches tall and spread 8 feet. In autumn it yields beautiful purply red fruits up to three inches long.
Cylindropuntia imbricata (cane cholla) grows to four feet or more and has a spiny, sausage-link appearance. Plants can be long-lived, lasting more than 20 years even in the North. They often won’t bloom reliably until mature, usually at the age of four or five. But once C. imbricata starts to bloom, it doesn’t stop, getting better every season. The bright reddish purple flowers may be as much as two-and-a-half inches in diameter; the flowers of many of C. imbricata‘s relatives last only a day, but these last for several. Seed pods are bright yellow and the stems, with their prominent spines, look terrific when backlit by the sun. The plants droop in winter, but will recover, as their opuntia cousins do, when spring sun warms them back to life. H
For sources of plants featured in this article, turn to page 96.