You’re likely accustomed to leaving potted plants out over summer, but if some of your favorite perennial plants are frost tender where you live, they’ll be damaged or killed if you leave them outside during winter. But by bringing plants indoors for the winter, you can protect them against the harmful consequences of cold weather. After bringing plants indoors, however, the key to keeping plants alive over winter depends on what type of plants you have and the growing environment you provide them.
Winter Plant Care
How to keep plants alive over winter (by overwintering plants in pots indoors) means you first have to make room for the plants, which is sometimes easier said than done. Although you may have enough room in certain locations in your house, if the plants don’t receive enough light, they may begin to decline.
Tip: Before bringing plants indoors, install some hanging basket hooks or shelves in front of bright windows. You’ll have an overhead winter garden that keeps plants from cluttering your floor space.
Other than giving your plants sufficient light while they’re indoors, a key to keeping plants alive through winter is providing the temperature and humidity they need. If you place the pots near a heating vent or a drafty window, the fluctuations in temperature may place too much stress on plants.
To increase the humidity around plants, set the pots on top of pebbles in a water-filled tray or dish, and keep the water level below the base of the containers.
When to Start Overwintering Plants in Pots
Most houseplants are tropical plants, which enjoy a little “summer vacation” in pots on your patio or deck. However, when the nighttime temperatures dip to 50 degrees F. (10 C.), it’s time to start bringing plants indoors to keep them alive during the winter.
Caladiums, lilies and plants that grow from bulbs, tubers and other bulb-like structures, may go through a “resting period.” After an active growth period, some plant’s leaves and stems begin to fade or turn yellow, and the plant typically dies all the way to the ground.
Even though these plants go through a dormant stage in winter, some (such as caladiums) need warm winter plant care while others (such as dahlias) respond better to chillier temperatures. A heated closet inside your home is suitable for overwintering caladium tubers, but an unheated location (40-50 degrees F. or 4-10 degrees C.) will work better for dahlias.
Before bringing in your entire garden of plants for the winter, know your USDA plant hardiness zone. This determines the lowest temperature at which different plants will survive the winter outside. When you buy plants, look on the manufacturer’s tag to find the hardiness information.