Tip of the Week — 6/1/09

Posted in Gardening Tips on June 1 2009, by Sonia Uyterhoeven

A Caribbean Cocktail: Tropical Plants in the Home Garden

Sonia Uyterhoeven is Gardener for Public Education. Join her each weekend for home gardening demonstrations on a variety of topics in the Home Gardening Center.

Tropical plants make wonderful specimen plants for a container or a welcome and exotic addition to your perennial border. Cannas and bananas are two of the most popular candidates. Both thrive when placed in sunny conditions away from the wind. Many of the variegated cannas such as Canna ‘Stuttgart’ do best when given some afternoon shade.

Cannas can either be grown as annuals or overwintered indoors. Once the frost cuts back the cannas, the rhizomes can be dug up and stored in slightly damp peat moss or in vermiculite in a cool, dark area for the following year. Banana should be potted up and also stored in a dark, cool area (below 55° F). The plants go dormant but should not dry out completely (check moisture levels once a month). Move them outside once it warms up or transition them slowly on an enclosed porch or greenhouse in spring.

There are many other tropical plants on the market these days that will set your garden on fire. Hibiscus ‘Maple Sugar’, as the name suggests, has dark maroon maple-like foliage. It complements cannas nicely and its deep tones add striking contrast to any combination.

Some other dark foliage favorites include Persian shield (Strobilanthes), purple spiderwort (Tradescantia), and Joseph’s coat (Alternanthera). Persian shield can handle drought, deer, and rabbits. Its foliage presents a glowing combination of purple, silver, and green, making it a vibrant addition to any perennial garden. To create a sophisticated color echo in your border, pair it with silver foliage such as dusty miller (Senecio), wormwood (Artemisia), or plectranthus (Plectranthus).  If the foliage is getting too ungainly just pinch it back to create a more compact specimen.

The cigar plant (Cuphea) and Mexican heather (Cuphea hyssopifolia) is taking the nursery world by storm. They make versatile additions to the garden. The most readily available cultivar is the gorgeous Cuphea ignea ‘David Verity’ that is covered all summer long with a fireworks display of red-orange miniature cigar-shaped flowers. My favorite feature of these tropical beauties is that you do not have to deadhead them—they are low-maintenance. 

Many of the annuals that we use for tropical containers benefit from either pinching or trimming back. Pinching produces a fuller plant. To pinch a plant, just snap off the tip with either scissors or your thumbnail above a leaf node (the place where the leaves attach to a stem). Some examples of plants to pinch: coleus (Solenostemon), Joseph’s coat (Alternanthera), salvias (Salvia), and dahlias (Dahlia).

Remember to place your tropical plants and tender perennials outside only after the last chance of frost in your area. Tropical plants tend to start off slowly and then pick up and take off once the warm weather sets in. Most of them are experienced sunbathers and love to bask in the summer heat. Some of them are drought tolerant, but most of them should be given adequate moisture to keep at their best.