Q. Can I store tropical plants over winter, so that I don't have to buy new ones each spring?
Many tropical plants can be dug up, put in individual pots, and stored in a basement or nonfreezing garage. In spring you'll start with plants that are bigger and healthier than what you can find in a nursery. You can also grow them in pots outdoors in summer and simply bring the pots into a dark, cool place in fall.
Banana, taro, hibiscus, mandevilla, bougainvillea, and angel's trumpet will go dormant if brought indoors and the soil is allowed to dry out. The leaves will turn yellow and drop; banana trees should be cut down to the soil level.
Note that soft-stemmed plants with fine roots cannot tolerate these dark, cool conditions; they overwinter best as rooted cuttings set in a bright window. Coleus, pentas and plectranthus are in this category.
In late summer, begin planning the move to indoors. You don't want to wait until the last minute--night temperatures below 50°F cause leaf yellowing and leaf drop. First, prune large plants to a manageable size. Then inspect your plants for insects and mite pests. Because the insect predators that keep them in check do not exist indoors, pests must be treated before you bring your plants inside. A gentle application of mild insecticidal soap should take care of the problem.
Bring the plants into the garage or basement, which should always be kept above freezing--40-45°F is ideal. Throughout the winter, keep the soil barely moist, watering sparingly when the soil is dry two to three inches deep in the pot. In spring, when temperatures are reliably in the 50s, you can bring your plants back outdoors.
For tropicals with an underground storage mechanism such as a bulb, rhizome or tuber, a more space-saving technique can be used. These include cannas, elephant ears and dahlias. In the fall, cut the foliage all the way down to the ground and dig up the rhizome. Shake off loose soil and use a hose to wash off any remaining dirt. With pruners, cut off any remaining stems or rotten root segments. Allow to dry, and then pack loosely into a wooden crate or cardboard box, wrapping in newspaper if desired. Store in a frost-free dark room, such as a basement or garage, until the danger of frost is well past. Now they can be unpacked and replanted in your garden.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service