Overwintering Patio Tropicals

 Tropicals cannot survive freezing temperatures but they can be kept alive inside, or overwintered, from one year to the next. While it does take some extra effort you’ll be rewarded each year with bigger and better plants with loads of character. There are different methods of overwintering tropicals according to the type of plant you wish to save. The goal is to imitate the way the plant naturally rests during its dormant period without allowing it to freeze.

Growing as a houseplant

This method works for allamanda, dipladenia, ferns, gardenia, ixora, jasmine, mandevilla, myrtle, oleander, New Zealand flax and palms. Remember, during the winter the plant will be at rest and won’t look nearly as luxurious as it did when growing happily outside.

• Before bringing inside the house check plant for pests. Rinse foliage thoroughly and treat with a systemic granular insecticide to manage potential pest problems in the future.
• Choose an east, south or west facing window. The sunnier the better.
• Since heated indoor air is exceptionally dry choose the most humid room (kitchen, bath), run a humidifier, place plant on a pebble tray filled with water and/or group plants together to maximize humidity level.
• Water when soil becomes dry to the touch. Do not overwater and do not fertilize until spring.
• Rotate plant every few weeks to maintain uniform growth.
• In mid-May after danger of frost has passed reintroduce your plant to the outdoors. To avoid sunburn place plant in a shady area first, gradually moving to a sunny location until fully acclimated.

Storing as a bulb or tuber

This method works for canna and elephant’s ears. Bulbs and tubers are underground storage structures from which new stems and leaves emerge.

• Allow light frost to turn tops black or brown then dig up and cut back foliage.
• Shake off the soil and allow to dry completely.
• Store in barely moist peat moss in a cool (40 to 45 degrees F), dark area such as an unheated basement or attached garage. Use a milk crate, large pot or other well-ventilated container.
• Inspect monthly for signs of rot or decay, disposing of anything rotted. Mist with water if needed to keep bulbs from drying out.
• In early spring re-pot, water and move to a sunny warm location inside to induce growth.

Storing as a dormant plant      

This method works for both herbaceous (no woody stems above ground) and woody plants. Herbaceous candidates include: agapanthus, angel’s trumpets, cordyline and ginger lily. Woody candidates include: allamanda, bougainvillea, dipladenia, hibiscus, ixora,  lantana, mandevilla and princess flower. You can induce dormancy by withholding water and keeping in a cool, dark place above 35 degrees F. Again, an unheated basement or attached garage is an ideal place for storage.

• For herbaceous plants cut back tops after a light frost turns them black or brown. Dig up and plant in a suitably sized container with soilless potting mix. If container grown, store as is.
• For woody plants bring inside before frost. Don’t prune or cut back unless plant is too big to manage. Dig up and plant in a suitably sized container with soilless potting mix. If container grown, store as is. Allow soil to dry out.
• Remaining foliage will yellow and probably drop off. New leaves will emerge in spring when the plant is returned to light and warmth.
• Check plant every 2 to 4 weeks for water. If the soil is dry 2-3 inches down, water sparingly. Keep plant barely moist (dry, but not parched) over the winter. The plan is to keep the stems and roots from shriveling, but not to encourage growth.
• In early to mid-April return the plant to a warm, bright area inside. Now is the time for pruning woody plants to shape, control size and to remove dead branches. Water more frequently (about once a week). The plant will start to develop new foliage.
• In mid-May after danger of frost has passed reintroduce your plant to the outdoors. To avoid sunburn place plant in a shady area first, gradually moving to a sunny location until fully acclimated.

Going Bananas

Bananas happen to be one of the easiest tropicals to overwinter, growing bigger and becoming more dramatic each season.

• If container grown, cut back to 4-6 inches after a light frost blackens the foliage. Bring inside and store pot in a cool (40 to 45 degrees F), dark area. Keep soil on the dry side. As spring approaches you’ll see a new shoot pushing up from the center. This is your new banana! Move outdoors in mid-May.
• If grown in the ground, dig up before first frost. Do not cut back. Leave the soil around the roots and wrap in a sturdy plastic bag. Store in a cool (40 to 45 degrees F), dark area. Keep soil on the dry side. Allow stems to die naturally. In early spring cut back to 4 inches, repot, and begin growing the banana again. Replant in the garden after mid-May when danger of frost has passed.