The Tropical Gardens
Elephant ears is the common name for a group of tropical perennial plants grown for their large, heart-shaped leaves.
https://hort.extension.wisc.edu/articles/elephant-ears-colocasia-alocasia-and-xanthosoma/
During Victorian times tropical gardens were very popular. Massive outdoor displays were cultivated during the summer and the plants were then moved into greenhouses or other protected areas during the winter to be saved until the next season. This concept is seeing a resurgence in today’s gardens. If a tropical vacation is not in the budget, bring the tropics to the Midwest by placing just a few tropical plants strategically in borders or as specimen plants. The impact will be impressive.
Annuals such as geraniums, impatiens, and begonias are tropical plants, but going beyond these into bigger and bolder plants takes some thought and planning. Tropical plants are heat loving and enjoy the Wisconsin humidity. They need to be placed in full sun as any shade will dimmish their intense color. However, some may be sensitive to direct light, so research the individual plant before placing it.
Tropical plants should be considered annuals or tender perennials in Wisconsin. Tender perennials are those plants that will last from year to year in a container, but must be moved inside to a protected location during the winter season. For an “in-ground” effect with a container plant, simply sink the entire container in the ground (in another pot) and remove it in the fall. Be sure to scout for pests before bringing them inside for the winter to prevent infestation.
Tropical plants require additional maintenance like frequent watering and regular fertilization with a slow-release fertilizer to reach their full potential. If planted in containers, a bark-based medium is the best choice. Good drainage balanced with a water absorbent material like coconut coir is a good balance. Because of their dramatic size, a 24-to-36-inch diameter pot will be a good size.
Elephant Ear (Colocasia) is one of the more popular tropical plants to include in a Midwest landscape. With large heart or arrow shaped leaves, the effect is stunning. There are numerous varieties to choose from, including ones with blue-green leaves, green leaves tinged in black, or glossy all black leaves. Grow these in a large pot and move them indoors as a house plant during the winter. Some can be grown in partial shade, but the darker varieties will do best in full sun.
Mandevilla is a tropical vine that can be loaded with trumpet shaped white, pink, red, or coral blooms. The vines can be trained up an arbor, fence, lamp post, or trellis for a dramatic display. This plant is either grown as an annual or in a pot and moved inside as a houseplant for the winter. Because of the cooler, drier conditions, it will not bloom in the winter. Prune it back by one-third before taking it back outside for the next season.
Finally, hardy Hibiscus (Hibiscus moscheutos and Hibiscus laevis) looks tropical but they are hardy to -30 degrees and grow naturally in wetlands and along river banks in the Midwest. This perennial, also known as Rose Mallow, is a full sun flower that is late to emerge in the spring. Patience is a must, but once they start growing, they will be 5-6 feet wide and can grow an inch each day. With their dinnerplate size blooms in white, red, pink, and yellow, they provide abundant color to a tropical garden.
Kick back, sip some lemonade, and enjoy bringing the tropics to the Wisconsin gardens.
Carol Shirk
Certified Master Gardener