Tropical plants are plants which are native to the tropical regions of world. The tropics are one of the most biologically diverse regions of the world, and there are thousands of known tropical plant species. Although all tropical plants have developed to live in the warm (above 50 F) and very humid environment of the tropics, and will not survive freezing temperatures, these plants are quite diverse.
Gardeners who garden in tropical and subtropical regions use tropical plants as perennial resources in the landscape. However, tropical plants are also a good resource for gardeners in colder climates who use them as perennials in interior landscapes and seasonally as annuals in outdoor landscapes.
Because they will not survive the winter in northern zones, many gardeners use tropical plants in containers that can be moved indoors during the winter. On the other hand, some gardeners plant them in garden beds as annuals with no intention to overwinter the plants indoors. They simply replant them each spring and enjoy them seasonally through the summer and fall seasons.
How To Overwinter Tropical Plants Indoors
Suitable indoor spaces
You can overwinter tropical plants inside heated spaces of your home or in non-heated but frost-free spaces such as a garage or basement.
Clean 'em up
Before you bring your tropical pants indoors for the winter, rinse them off good with the water hose. Then, closely inspect the foliage for insects or other critters that you don't want to bring indoors. Make sure to check the undersides of leaves. If you find any insects pick or spray them off before bring the plants indoors. You can also spray the plants with a safe insecticide listed for indoor use, such as insecticidal soap. Be sure to spray both the upper and under sides of leaves. When using insecticides always read and follow instructions on the label.
To prune or not to prune?
It is best to wait until spring to prune tropicals such as hibiscus, allamanda and mandevilla. That being said, sometimes you may have to do some pruning to create a plant of manageable size that you can move indoors or to tidy up the plants. Most tropical plants respond well to pruning so prune or cut them back as necessary to make them manageable.
Garages and basements
When overwintering in non-heated spaces you'll be maintaining the plants in a dormant or semi-dormant state in which they will require less attention to watering. Since the plants won;t be actively growing you'll want to water them sparingly to keep them on the dry side; maybe once every 3 or 4 weeks, and there will be no need for fertilizer.
Overwintering in the home
These plants are kept actively growing in heated spaces of the house. They may continue to bloom and produce new foliage throughout the winter. If the plant typically likes lots of sunshine, keep it in or near a sunny window. You'll want to water when the upper upper 2 inches of the soil becomes dry. Be careful not to over-water the plant as this can cause root rot or other diseases. Since indoor heated environments are usually on the dry side, the foliage can be misted with water twice a week or so to maintain humidity around the plant. If you use a humidifier in your home that keeps the humidity at or above 50 misting will not be necessary. Since your tropical plant will be actively growing you can feed them with a water-soluble plant food once a month at half the recommended dose.
When to move plants back outdoors
When night time temperatures are remaining consistently above 55 degrees F you can move your tropical plants back outdoors. In the event there is a late cold front that moves through bring plants indoors until temperatures have returned to above 55 degrees.