The night-scented blossoms of Brugmansia are intoxicating and dramatic
by WAYNE WINTERROWD
UNTIL RECENTLY, SPECIES OF BRUGMANSIA were included in the genus Datura. Now, however, they have been firmly detached, giving Sebald Justin Brugmans (1763-1819), an otherwise obscure professor of natural history at Leyden, the recognition he was intended to have. Even to the most naive gardener, however, the differences between the two genera will be clear. All species of Brugmansia are stout, treelike plants, whereas daturas are coarse, sprawling annual or perennial herbs. The blooms are similar, consisting of flared tubes of five fused petals, but those borne by brugmansias are more-or-less down-hanging, whereas flowers of daturas are borne laterally or up-facing.
Though both genera are cultivated for bold effect, few plants are as assertive in the summer garden as a well-grown brugmansia. Flowers, from 10 to 15 inches long, are produced abundantly throughout the summer months and are usually hauntingly scented at twilight and through the night. A perfect specimen, hung with dozens of foot-long trumpets, is unforgettable.
BIG AND BOLD
The genus Brugmansia is quite small, consisting of only five species, mostly native to the moist tropical regions of South America. They are reliably hardy only in the warmest parts of North America, retaining both their leaves and their pulpy, woody growth over the winter only in USDA Zones 9 and 10. Although in colder gardens they are sometimes planted in the ground as part of a summer bedding scheme, generally they are featured as very large tubbed or potted specimens on terraces or decks. That is perhaps their best use, for they can easily look peculiar in a northern flower border lacking the companionship of other bold plants that would surround them in tropical gardens.
Though all species of Brugmansia are of quick and lusty growth (a rooted cutting can grow easily to six feet in one season), their very exuberance can make successful culture a little difficult. Like many tropical plants, their fleshy root systems are not as large as one might suppose for so large a plant. Still, a 12-foot, heavily wooded, large-leaved, and huge-flowered plant will need some room. So as young plants develop, they should be moved frequently into larger and larger containers until they come to occupy the largest pot, tub, or box one can conveniently manage. (After that, an annual spring pruning should attempt to keep plant and container in aesthetic balance.) Containers must also be stabilized, for a mature brugmansia in full sail can easily blow over. Protection from wind is necessary also, because the plants require abundant water—sometimes twice a day in dry summer heat—and desiccating winds compound the problem. When their need for water is denied, brugmansias will shrivel and wilt almost immediately, often shedding immature flower buds and even leaves in a premature preparation for winter dormancy. As one would expect from such a vigorous plant, brugmansias are also voracious feeders, requiring the richest, free-draining compost, and then supplementary feedings of water-soluble plant food throughout the summer. A commercially prepared food specifically formulated for tomatoes works wonders when applied at half strength every week throughout the summer months.
Brugmansias may be expected to produce some flowers from young cuttings in their first season if started early or bought from a nursery. But the most spectacular results will occur in subsequent years from older plants. If their requirements for winter dormancy can be met, they are fairly easy to carry over. In autumn, flower production will decrease and leaves will begin to yellow and drop, signaling that the plant is entering winter dormancy. Before the slightest touch of frost, however, plants should be taken into a cool, frost-free place for winter storage. Temperatures that hover around 45°F are ideal, and very little light is needed. Only so much water should be given as is needed to keep the youngest, most succulent shoots from shriveling, and no supplementary food should be supplied.
The hardest part of overwintering brugmansias will occur around late March, when the plants finally become impatient of their winter confinement and break dormancy. As they are extremely frost tender, a place must be found indoors for them to begin growth, such as a heated sun porch or a cool, sunny guest bedroom. When plants first show new growth, they may be pruned to a convenient size, generally by shortening lateral branches by a third or even by half. They should also then be repotted into fresh com-post. If they have reached the largest container that is manageable, they may also be root-pruned, by turning them out of their pots, teasing away an inch or two of soil around and at the base of their roots, and trimming straggly exposed roots even with the reduced root ball. They may then be replanted into the same pots they previously occupied, with an inch or two of fresh compost about and below their roots. Plants should be returned to their positions outdoors only when all danger of frost is past, and they should be acclimated gradually to bright light by first being put in a partly shaded spot for two or three days. (Frequent wetting of the new foliage and stems will also help them.) New growth will be rapid, and the first flowers should appear by early summer.
Though brugmansia comprises only five species, it is currently enjoying such a vogue among gardeners that a surprising number of cultivars, for so small a genus, have recently become available. Species appear to intermarry freely, and so the brugmansia most frequently offered previously has been Brugmansia x candida, a naturally occuring hybrid between two Peruvian natives, B. aurea and B. versicolor. As the botanical name candida always indicates, naturally produced hybrids are a pure, shining white, and occur either in graceful single or dramatically congested double forms. But pale yellow and bluish white flowers also naturally occur, and so by careful selection, breeders have created single and double forms that are lemon or melon colored. The very popular cultivar ‘Grand Marnier’ also probably belongs to this group, with single flowers of a pale orange tan. So sumptuous have cultivars of B. x candida become that its chaste name seems no longer to apply.
Additional melon and pink shades can be had from B. x insignis, and white, cream, peach, melon, and buff from one of its parents, B. versicolor. From the other, B. suaveolens, one gets a flower of pristine white, much like that of a single white B. x candida, but shorter by two or so inches, more flared at the mouth, and of a strikingly delicate poise and texture. For shades of true red, scarlet, deep orange, and even a lemon-lime combination of yellow with green veins, one must turn to B. sanguinea. Its tubular flowers are the smallest of all the species, at six to eight inches long.
All brugmansias are lovely, but unless one is intent on making a large collection of them (which would amount to a herd of pet elephants in the backyard), perhaps the pure white forms of B. x candida or B. suaveolens are the best choice, for their powerful fragrance and their eerie, lanternlike glow on summer nights. H
For sources of plants featured in this article, turn to page 72.
Air Layering Brugmansia
Air layering describes the technique of creating new plants from shoots still attached to the parent. It works with any woody plant that roots at all, and with brugmansias it is very quick.
First, around mid-July, select a strong, unbranched shoot, preferably one that is shaded by other growth. Using a razor blade or sharp knife, carefully remove an inch long cylindrical section of bark, about eight inches from the growing tip. Squeeze most of the moisture from water-soaked, unmilled sphagnum moss, and form the moss into a fist-sized ball. Secure the ball to the cut with soft twine, and wrap it with plastic wrap, tying the top and bottom snugly against the stem to prevent moisture from escaping. Wrap a layer of aluminum foil around the plastic wrap. After about four weeks, peel away the foil. Fat roots should be obvious. (If not, cover with new foil and wait a week or two longer.)
When roots have formed, unwrap the ball, and sever the stem just below it. Pot the rooted cutting, sphagnum and all, water it thoroughly, and stand it in a shaded area until leaves cease to wilt in the daytime.—W.W.