With the interest in tropical gardening surging amongst people who live far north of the tropical zones, anything that makes this easier is a boon. For those who don't have a greenhouse, a warm, lit basement or an extra room in which to overwinter their favorite tropicals, a garden consisting of tropical-looking plants that go dormant in winter can be the next best thing . . .
Editor's Note: This article was originally published on March 6, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
The Underground Movement
When I was in my teens, I made my first attempts at growing tropical plants in a northern garden. I was living in Maryland, a place that is hardly an oasis for tropical growing. This did not stop me from trying, and in those early days, I learned a few things that are still applicable today. One of the most important is that, when you don't have a place to keep a bunch of tropical plants growing for the winter, you need to look into tropical or tropical-looking plants that go dormant in the fall. The best ones will be able to overwinter in the ground under heavy mulch, but others that can be dug when dormant will work nearly as well. Today a much greater variety of plants is available and there is little to no excuse for not being able to grow a tropical garden that, effectively, "disappears" in the winter. With what I call a tuberous garden, you won't have to worry much about how well your plants will do in the winter because you just need a dry, cool, frost-free place to store your tubers and corms.
What To Choose
For me the elements of a tropical garden boiled down to three main components: big leaves, big ferny (i.e. palm-like) leaves, and exotic flowers. These could mix and match, but I needed several of each and a number of sizes of each to mix up and produce a tropical effect. I found that I also needed some "tropical" trees to complete the look, but I'll cover that topic in my next article. The easiest way to get big leaves is to use either Colocasia or Xanthosoma corms that you can usually purchase at the well-stocked produce section of a large grocery store. They are often called "malanga" and "taro". If you can't find them there, you can often get them at a big box store in the springtime as "elephant ears". For palm-like leaves and sheer exotic look, it's hard to beat a large Amorphophallus plant. Over the years, you may also get surprised with a very strange and stinky smelling bloom. Hopefully, you will have planted it out in the garden by the time it blooms!
Exotic flowers can be Amaryllis bulbs, Sprekelia, which looks so much like a red Orchid that you must include it in your garden, and Eucomis. An example of a plant that does double duty is Canna, which has leaves similar to a small banana plant, yet has brilliant tropical flowers. Some aroids that can work here are Typhonium ("voodoo lily"), Arum, Arisaema, Dracunculus, and even the skunk cabbage, Symplocarpus foetidus, which, when leafed out, looks somewhat like a smaller Alocasia plant. Many other plants can be pressed into service as stand-ins for tropicals. If you browse through a Spring bulb catalog with an eye for picking out exotic-looking items, you are sure to find more candidates for your garden. Some of the plants I mentioned above may have to be "forced" into dormancy by drying them out in the basement, but they will go dormant and be ready in the springtime for your next garden. A few can be left in the ground all winter if well mulched, depending upon your zone.
Recently, I found an Alocasia that goes into true dormancy and has exotic large leaves as well as light pink blooms; it is Alocasia hypnosa, but is also sold as Alocasia 'Maechang'. Mine are naturally dormant now (no forcing), even though where I live (south Florida), tropical plants can grow just about year round.
So you can see that you can have your tropical garden and still not have to worry about what you are going to do with all those tender plants when frost and freeze is looming in the fall.
Next: The Look of Tropical Trees in a Northern Garden
About LariAnn Garner
LariAnn has been gardening and working with plants since her teenage years growing up in Maryland. Her intense interest in plants led her to college at the University of Florida, where she obtained her Bachelor's degree in Botany and Master of Agriculture in Plant Physiology. In the late 1970s she began hybridizing Alocasias, and that work has expanded to Philodendrons, Anthuriums, and Caladiums as well. She lives in south Florida with her partner and son and is research director at Aroidia Research, her privately funded organization devoted to the study and breeding of new, hardier, and more interesting aroid plants.