Tropical Garden Design for Colder Climates

Summer—it's a time of patriotic gatherings, pool days and breathtaking electric bills, thanks to the air conditioner. For a gardener, summer also includes major worries about the health and happiness of your beloved plants. Will the tomato flowers set fruit? Are dahlias wilting too quickly in the heat? Yet we can look to the tropics for plants for practices to make the garden enjoyable even in the steamiest of summers. I was a designer on Sanibel, an island off the coast of Florida, for a year, and I spent my time learning how fine-tuned luscious gardens beat the heat. Here are my five top tips for bringing tropical style to your temperate garden.

1. Choose Plants with Large and Shiny Leaves
Large, lush leaves are perhaps the single most characteristic visual feature of tropical gardens: massive paddles of banana paddles (Musa), giant umbels of Licuala, looming fans of silver Bismark palm (Bismarckia nobilis) and the gargantuan shields of elephant ears (Alocasia and Colocasia). When leaves dwarf humans, a garden feels tropical. Temperate gardeners have the advantage that, without subtropical storms and winds, their tropical foliage will often stay in better condition, with stronger colors and cleaner edges than you’ll see in tropical gardens. A sheltered position where massive foliage won’t be torn and desiccated by the wind is essential for big-leaved plants to thrive.

Many big-leaved tropical plants are well adapted to temperate gardens throughout the United States, where they can serve as houseplants in the winter. Whose grandmother didn’t have a potted philodendron, swiss cheese plant (Monstera deliciosa) or schefflera sitting in her kitchen window? Cannas, bananas and elephant ears are great warm-season garden plants that can be shuffled into an unheated garage for the winter. Meanwhile some completely winter-hardy plants have a remarkably tropical appearance with large foliage. Ornamental rhubarb species look tropical despite surviving extremely low temperatures. Red rhubarb (Rheum palmatum ‘Atrosanguineum’) has dramatic purple-flushed jagged leaves with red stems, while cultivar ‘Ace of Hearts’ boasts equally impressive foliage with a ruffled edge. Darmera peltata has large rounded foliage. Glossy cobra lily (Arisaema ringens), with its huge, glossy tripartite leaves, and shredded umbrella plant (Syneilesispalmata), with its dissected leaves, are other reliably winter-hardy perennials with a sensationally tropical appearance.

2. Cover Every Surface with Vegetation
In the tropics, no plant stands alone. Spreading live oaks (Quercus virginiana) and tabebuia (Tabebuia caraiba) drip with mosses, bromeliads, orchids and ferns. These epiphytic plants create entire communities that live off rainwater and air-borne dust, while supported within the structure of large rough-barked trees. Closer to the ground, vines and lianas sprawl across structures, as entire spaces are enveloped in vegetation. Walking through a tropical garden gives a complete sense of immersion. The ground is thick with ferns and mosses.

You can recreate this sense of profligate abundance in a temperate garden by incorporating vines, thickly layering your plants and making sure that every surface is bedecked with foliage and flowers. Tropical epiphytes grow easily as houseplants that can be brought outside in the summer and hung from trees and garden structures. Turn your sun porch into a tropical sensation—deck the entire thing with masses of lush-leaved tropicals.

3. Choose Plants with Large Flowers
People imagine tropical gardens as a veritable Hawaiian shirt of bloom. Many tropical gardens don’t actually have as high a bloom percentage as traditional temperate-climate perennial gardens, but the flowers that are there are huge. To capture this style in your temperate garden, go for big, bold and attention grabbing. Tropical hibiscus (Hibiscus rosa-sinensis) are the epitome of a subtropical large bloom; some cultivars, such as ‘Pink Elephant’ and ‘Aztec Giant’, bear flowers that are regularly nine or ten inches in diameter. If you want big flowers without the need to protect your plants in winter, try hardy hibiscus (H. moscheutos). Some cultivars, such as ‘Kopper King’ and ‘Midnight Marvel’, have purple foliage as well as massive blooms.

While hibiscus have massive individual blooms, other tropical plants have large flower heads composed of many smaller flowers. Dombeya, Clerodendron and Mussaenda are all genera with massive flower heads that will draw attention from across any garden.

4. Site Fragrant Plants Strategically
One of the strategies that tropical plants use to attract pollinators is fragrance. Many favorite tropical plants have strong sweet fragrances that drift on the air. Distribute them throughout your garden to bring beautiful moments of discovery and surprise. Sweet, spicy and rich fragrances are typical of tropical gardens. Plant ginger lilies (Hedychium ) for their intricate multi-tiered flower heads and unforgettable perfume. Jasmines such as Jasminum sambac and J. officinalis are easy to grow as part-time houseplants. Angel’s trumpets (Brugmansia) and their squatter cousins the locoweeds (Datura) have alluring nighttime fragrance and they will blow everyone away with their massive blooms. For something winter hardy yet tropically perfumed, include Hosta plantaginea, with its exotic and far-carrying scent. Moonflowers (Ipomaea alba) are annual vines easy to grow from seed, with luminous white blooms that swirl open at night, drawing ghostly pale-green luna moths.

5. Power Clash with Brightly Colored Flowers and Foliage
Flat white tropical light bleaches pale colors into oblivion. The tropical look demands vivid colors. For bright-hued flowers that attract hummingbirds, consider tropical salvias (such as Salvia guaranitica or S. vanhouttei), shrimp plants (Justicia) and Globba. Tropical designers also love small but brightly colored plants— especially those from the genera Cuphea, Lantana and Catheranthus. Bromeliads often have power clashes within their own coloring, particularly when you consider their blooms. Bilbergia foliage looks as though it’s splashed with milk, with dangling flowers in magenta, purple, chartreuse, blue and yellow. Be bold with your color combos—take inspiration from Kimmy Schmidt—and summer guests will find your garden anything but sleepy.

Whether you garden at a steamy bayou’s edge in Louisiana, in a gloomy courtyard in Maryland or on an exposed porch at the edge of a Wisconsin prairie, you can take inspiration from tropical gardens. Choose plants with large and shiny leaves, cover every surface with vegetation, choose plants with large flowers, site plants strategically and power clash with brightly colored flowers and foliage. Then pull up a deck chair, pour yourself a fruity drink and let summer roll on in all its glory. No worries here.

This article first appeared in the May/June 2017 issue of Horticulture.