Tropical Flower Garden Ideas

The Importance of Mulch

A successful tropical flower garden design will include some negative space. This refers to the areas that don't have plants. Typically, these are mulched areas, or they may be covered with concrete, stone, or sand. Less often in the tropical garden, the negative space may feature a lawn. Negative space in a tropical garden becomes more important for gardeners who collect rare flowering specimens. Without some negative space to punctuate these special plants, they become just another character in the jungle. However, surrounding a special tropical flower with mulch not only provides a foil for beautiful blossoms and foliage, but it also reduces competition between plant roots for nutrients and water, helping your rare plant to thrive.

Gardeners can choose a mulch that complements the tropical garden theme. Chopped cocoa bean hulls not only keep their rich dark brown color throughout the growing season, they also impart a pleasing chocolaty aroma for several weeks after spreading. Wood chips that are dyed black are also a wise choice for tropical gardens: the dark color absorbs sunlight, adding a few degrees of warmth to help tropical plants thrive in cool areas. 

Keep Them Hydrated

 Proper irrigation is critical for the health and beauty of tropical flowers. In their native habitat, flowers don't just receive a daily dump of water on their roots. A humid atmosphere also keeps exotic flowers fresh and dewy. Installing a water feature in the tropical flower garden serves an ornamental purpose, but the fine spray and mist created by a waterfall also keep plants healthy. In cold landscapes, you can tuck container plants like bromeliads around your water feature, and then easily bring them indoors when the growing season winds down.

Instant Tropical Landscape

Gardeners in temperate climates may not feel confident about their ability to grow tropical flowers, but a selection of the right quick-growing annual flowers makes the tropics accessible in any region. The showy orange spikes of 'Hot Biscuit' amaranth star in this tropical design. Amaranth plants are easy to grow from seed, and you can even eat the young leaves, which have a mild spinach flavor.

The red flowers of dahlia 'Bishop of Llandaff' on the left will bloom from July to October, and stand in bold contrast to the dark foliage. Cannas and flowering castor bean intermingle on the right side of the photo, adding further texture and rich amethyst jewel tones that look stunning whether plants are in or out of bloom. Airy stems of South American native Verbena bonariensis keep the whole design from looking too dense, and will self-seed for future seasons of purple blooms.

Quick Cannas

One aspect of a tropical garden that can be difficult to achieve in cold regions is height. Without a greenhouse, tropical plants fall victim to the season's first cold snap just as they are reaching shoulder height. However, canna lilies provide that dramatic height in the tropical-themed garden in just one summer.

The quickest way to get cannas going in early summer is to buy potted plants. However it's expensive to replace cannas each year, and the rhizomes are easy to save. After frost kills the top growth, cut the dead foliage down and dig the clump out. Rinse soil from the clump, and allow one week to dry. Store in a dark, cool place. An unheated garage works well. Plant after last frost, and look for blooms about ten weeks after that.

Get Orchids Outside

 Orchids may be the quintessential tropical flower, but few live in a climate that features ideal growing conditions for the plants year-round. However, that shouldn't stop you from giving your gift orchid or greenhouse collection of plants an outdoor vacation. Nestle potted orchids strategically around the garden for an instant tropical feel. The increase in light and humidity may be just what tired plants need to trigger a growth spurt, and perhaps even some new buds.

Bright, filtered light is better for most orchids than full, direct sunlight. The dappled shade under a tree canopy is ideal. A sheltered area will protect flowers from wind damage. Be sure to bring orchids indoors or into a greenhouse when temperatures dip below 50 degrees F. Even a heated garage will do in a pinch if you experience a cold snap. Vanda and dendrobium orchids tend to be the most cold-sensitive, while cymbidium and cattleya orchids are hardier, so know your orchid to prevent chill damage symptoms like discolored leaves.

Design With Vines

 Scrambling over fences and across trellises, vines add much allure and a sense of mystery to tropical gardens. Technically, all annual vines are of a tropical nature, but some vines appear more exotic than others. The passion flower vine offers a unique opportunity for tropical gardeners, in that it can successfully overwinter in climates as cold as USDA growing zone 5 when given a protective mulch and a sheltered location. Gardeners can expect three-inch fragrant white or purple flowers bursting with frilly stamens on vines that will grow up to 30 feet in warm areas. In colder areas, vines die back to the ground and remain a tidy three to five feet, just perfect for a medium-sized trellis or fence.

Gardeners in tropical landscapes or with greenhouse access can choose one of the showy tender varieties of passion flower, like the striking red 'Lady Margaret' cultivar. Give these vines sturdy support that will allow the tendrils to grasp, and bring indoors in areas colder than zone 8.

Give your passion flower vines at least a half day of sun, and keep moist. An early spring pruning will remove old growth and open up the plant for easier blossom viewing. Butterflies will want to visit your passion flower plants, especially the Gulf fritillary, which will lay eggs only on these supporting host plants. If you can put up with a few chewed leaves, you'll allow the next generation of butterflies to mature.

A Tropical Tree

 Getting the look of a tropical tree can be challenging in cold climates, as even small trees growing in containers are difficult to move indoors when frost threatens. Instead of growing a true tree, gardeners may cultivate a shrub into a tree form with careful pruning.

Here, an angel's trumpet (brugmansia) with a strong central trunk grows happily in a galvinized copper container. When shopping for an angel's trumpet, choose the genus Brugmansia over the genus Datura for training as a standard, as the brugmansia angel's trumpet has a woodier habit that makes a convincing tree. While the plant is still young, prune away side shoots to allow a strong central leader to form.

A brugmansia angel's trumpet may reach eight feet in height at maturity, but container-grown specimens usually top out at a more manageable six feet. Angel's trumpets start blooming in late summer, and the evening fragrance is a knockout, drawing legions of hummingbird moths. All plants in the angel's trumpet category are extremely toxic, and gardeners are wise to wear impervious gloves when pruning or otherwise interacting with these exotic plants.