Big-leaf tropicals are staging a boisterous comeback. Popular in Victorian times and again in the 1950s, these immense-leafed beauties and their hybrid offspring are bringing a new element of drama and visual excitement to traditional landscapes.
Since few big-leaf tropicals survive temperatures below 32 degrees, they're often treated as annuals or tender perennials in cooler parts of the globe. Native to temperate parts of Asia, Africa, Australia and South America, most grow from rhizomes, which must be dug up and overwintered in a frost-free place. In warmer areas, rhizomes can remain in the ground. Although they're slow to emerge from dormancy, they make the wait worthwhile and serve delightfully as specimens, focal points, container and pond plants, conversation pieces, screens and anchors for smaller plants in a tropical-inspired border.
For gardeners who like the look and artistic challenges of tropicals but need something hardier, gardening expert Kathy Renwald thinks it's possible to have the best of both worlds: "I like to grow plants that are hardy but give a tropical effect," she says. "Two of my favorites are ornamental rhubarb (Rheum palmatum) and petasites (Petasites frigidus)." Others to consider are rodgersia, ligularia, acanthus, the old standby hosta and, if you're really adventurous, gunnera. But for those wild and crazy gardeners ready to "think big," consider these truly tropical choices:
Canna Lily (Canna spp.)
Once snubbed for its coarse texture and plain green foliage, this easily recognized tropical has undergone a major image makeover. Spectacular new canna hybrids, with colorful variegated leaves and gladiolus-type flowers, are popping up in perennial beds, containers, parks and highway medians, in sizes ranging from two to six feet. Two selections, 'Bengal Tiger' and 'Tropicana', are stunning combined with ornamental grasses and lime-green or burgundy coleus. Cannas multiply rapidly in full sun and moist, well-composted soils. Zones 7-10.
Elephant's Ear, or Taro (Colocasia and Alocasia spp.)
These lovable giants are appealing for their graceful forms and ruffled, heart-shaped leaves. They grow aggressively in sun or part shade and in typical garden soils, as well as bogs. In return for their flexibility, they ask only for frequent, heavy feedings and winter protection. A sought-after species of elephant's ear is Colocasia esculenta. Popular cultivars are 'Illustris', a three-foot knockout with near-black leaves and lime-green veining, and 'Black Magic', a purplish-black selection that also grows to 3 feet. Both make excellent container plants. Zones 7-10, depending on species.
Bananas (Musa spp.)
Grown for decades in southern gardens, the banana is compelling for its massive, billowy leaves (which are, unfortunately, susceptible to wind damage) and its exotic palm-tree form that evokes images of ancient forests. Most of the 40 banana species love sun, heat and well-drained, rich soils. M. basjoo, the world's most hardy banana, reaches eight to ten feet and has survived temperatures of -20 degrees with proper mulching. M. acuminata is widely used for commercial fruit production. The bloodleaf banana and 'Super Dwarf Cavendish' are popular acuminata selections. Zones vary.
Lotus (Nelumbo spp.)
It's easy to understand the mystical appeal of these plants. Their three- to four-foot stems, dramatic seed heads and gigantic blue-green leaves give them an ethereal look. Both species of lotus--N. nucifera, the sacred lotus of Asia, and N. lutea , the North American yellow-flowered lotus--are easy to grow in soil or water, provided they get plenty of sun, moisture and several months of temperatures in the 75- to 85-degree range. In areas where water temperatures drop below 32 degrees, lotuses must be overwintered (container and all) in a frost-free basement or garage. 'Alba Grandiflora' is an exquisite double-flowered cultivar. Zone 4.
Hidden Cone Ginger (Curcuma zedoaria)
Gardeners are discovering the many charms of ginger, a vast family of species native to Africa, Asia and Australia. They range in height from a few inches to 15 feet or more and boast a lovely array of flowers, forms and foliage. A striking species, C. zedoaria, has pine-cone-like flowers and two-foot-long leaves with a maroon stripe along the center. Plants form a clump four to five feet high by two to three feet wide and contrast nicely with variegated and fine-textured plants. They prefer a moist, partly shaded environment. Zones 7b-10.
Castor Bean Plant (Ricinus communis)
Native to Africa and grown commercially in India and other countries for castor oil, this plant is a definite standout in the garden. A fast grower, it reaches 40 feet in the wild and 15 feet or less in cultivation. The burgundy leaves and red berries are very appealing, but it's wise to avoid this plant if there are children or animals around. All parts of the plant are poisonous, but the seed coating is especially toxic. Zones 8b-11.