What is Overwintering?
Overwintering plants simply means protecting plants from the cold in a sheltered place, like your home, basement, garage, etc. Some plants can be taken in your house where they continue to grow as houseplants. Some plants need to go through a dormancy period and will need to be overwintered in a cool, dark space such as a garage or basement. Others may require storing of their bulbs inside through the winter. Knowing the plant’s needs is the key to keeping plants over winter successfully.
How to Overwinter a Plant
Many plants can simply be taken into the house and grown as houseplants when temperatures outside become too cold for them. These include:
Rosemary Tarragon Geranium Sweet potato vine Boston fern Coleus Caladiums Hibiscus Begonias Impatiens
Lack of sunlight and/or humidity inside a home can sometimes be a problem, though. Keep plants away from heat ducts that can be too drying for them. You may have to set up artificial light for some plants to simulate sunlight. Additionally, you may have to take steps to provide humidity for the plants. Plants with bulbs, tubers or corms that need a dormancy period can be overwintered just as dried roots. Examples include:
Cannas Dahlias Certain lilies Elephant ears Four o’clocks
Cut back the foliage; dig up the bulb, corm or tubers; remove all dirt from them and allow to dry out. Store these in a cool, dry and dark area throughout the winter, then replant them outside in spring. Tender perennials can be overwintered in a cool, dark basement or garage where temperatures stay above 40 degrees F. (4 C.) but are not too warm to cause the plant to come out of dormancy. Some tender perennials can be left outdoors through the winter with just an extra heap of thick mulch covering them. Like everything in gardening, overwintering plants can be a lesson of trial by error. You may have great success with some plants and others may die, but it’s an opportunity to learn as you go. Be sure when bringing any plants indoors for winter that you treat them for pests beforehand. Growing plants you plan to overwinter indoors in containers all year long can make the transition easier for you and the plant.