University of Illinois Extension
http://www.urbanext.uiuc.edu/tropicalpunch/

Gardening with Tropicals

Come and Explore...an exciting new trend in garden design — tropical plants that are incorporated into annual or perennial borders. If you are like most gardeners, you might get bored with traditional annual flower borders. Well, welcome to the jungly world of huge, shiny leaves, bold outrageous colors and ferny textures. It is possible to change the look of a traditional annual or perennial border by skillfully placing just a few tropical plants in the right place for impact.

This garden style relies on using traditional tropical plants as well as tropical looking temperate zone plants to create the feel of a tropical setting.

Using tropicals in the outdoor garden is nothing new. Plant collectors have grown and collected them for hundreds of years. Annuals such as geraniums, impatiens and begonias are actually tropicals. During Victorian times, tropicals were all the rage. Lavish outdoor displays were created during the summer and then these plants were moved into “glass houses” to be overwintered for use in next season’s garden. This style of gardening was novel and new at the time. It is seeing a revival, because it tends to draw attention to the garden. And if it’s attention you want, just incorporate a few tropical plants into a flower border and wait for the second looks, stares, ooh’s and aha’s from visitors to the garden. They will wonder if they are in the Midwest or many miles south.

It’s easy to create a unique display of tropical foliage even if you are gardening in the Midwest. In most cases, we enjoy summers that get plenty of sun, heat and humidity along with occasional heavy rains. These conditions fuel the growth of tropicals into high gear so that even if you start out with small specimens, they grow unbelievably fast and turn into large, imposing plants in a matter of weeks. In July and August when temperatures and humidity are at their highest, traditional garden plants often struggle to look good, but tropicals are in their element and look outstanding.

A border planted with tropicals gets better as the season progresses. Many popular houseplants such as rubber plant, dieffenbachia, spider plant, spathiphyllum, pothos, and croton, when rescued from dark corners of your home, make excellent additions to the tropical border. You can grow tropicals directly in the ground or in containers.

Plants in containers can be placed by entrances, patios and decks or plunged into the ground in annual or perennial borders. This makes it easier to move them inside for the winter.