You love the splash of color your outdoor potted pots bring to your porch, walkway or as a main focal point in your front yard.
Container gardening need not end with first cold snap. Keeping them healthy in winter comes down to knowing which plants can tolerate overwintering outside and when to bring those that can’t indoors.
“Many potted plants can easily be overwintered indoors as houseplants,” says Diane Larson, horticulturist at Rutgers Cooperative Extension of Monmouth County, N.J. “This should be done before the first frost in your area.”
Which Plants Need to Go Inside
Larson recommends bringing all tropical plants indoors for the winter. She also includes:
- Pelargonium (better known as geraniums).
“I’ve also had luck with tender herbs such as parsley and basil, as well as pots of succulent gardens,” she says.
Hardy Plants That Can Remain Outside
Other plants, with proper care, can stay outdoors.
- Japanese yew and Brown’s yew can dress up a front porch year-round. It’s drought-tolerant, cold-hardy and likes both full sun and partial sun settings.
- Potted blue spruce is a popular evergreen that’s often raised as Christmas trees. It needs full sunlight and the soil must be kept damp. So watering is essential. Just be sure that the pot has a drain hole so you won’t overwater it.
- Cypress topiaries need morning light and afternoon shade. You also have to make sure you don’t overwater it or it will rot.
- Boxwood hedges, English boxwoods, and winter gem boxwoods are shaped like topiaries and need full sunlight in order to survive harsh winters. The rule regarding watering is between one and two times each week. However, it only should be watered on hot, dry days.
Winter Containers for Your Outdoor Potted Plants
For those cold-hardy plants that you decide to leave outdoors, you can improve their odds by placing them in winter containers. Terra cotta is not your friend. Its water-absorbent nature will cause it to freeze repeatedly and eventually crack. More-solid material, such as fiberglass, stone or heavy plastic, do better.
Make sure your soil is well-drained. Because your plants won’t grow much in the winter, you want to avoid having the roots sit cold and damp for a long time. That’s a recipe for root rot.
Moving your outdoor plants to a warmer, more-protected microclimate also helps them out. Farmer’s Almanac suggests a gentle, south-facing slope protected from hard winter winds.
Gardening Tips for Transitioning Periods From Outdoors to Indoors
Many plants will lose some or even all of their leaves when brought indoors. According to Larson, this is completely normal. “It just means they are going dormant or adjusting to the lower light conditions and may sprout new leaves that are more acclimated to the site,” she says.
“In the spring, as the days get longer again, you will notice more new growth. At this point, it’s a good time to repot them if you’d like to do so and you can also start to feed them with a dilute solution of water-soluble fertilizer. After the threat of frost is over in the early spring, start the pots off in the shade and slowly move them into a sunny spot.”
Keeping Them Healthy Indoors
First, make sure they’re healthy when you bring them indoors and check to see that they’re free from pests. Also, check the drainage hole in the pot to make sure it’s not clogged. If it is, the root systems will rot over the winter months. “The best way to know this is to make sure the plants drain when they are watered,” Larson explains. “As plants that grow in warm climates, most of these will appreciate being placed by a bright window.”
Avoid cold and drafty areas such as an unheated garage. After all, moving your outdoor plants before the cold weather hits means keeping them warm and comfy.
The most harm that can come to your plants is overwatering them. If that happens, let the soil dry out before the next watering. “The goal,” Larson says, “is to keep them alive until they can be placed back outside in the early spring. With the shorter, cooler days and lower light conditions indoors, the plants will not be actively growing. They will need little water and no fertilizer.”
How Do You Guard Against Bringing Pests Indoors?
Before you bring your outdoor plants inside, check for leaf- and soil-dwelling insects. Carefully examine the stems and both sides of the leaves for aphids, spider mites, scale, mealybugs, gnats, spiders, and lacewings. Soil-dwellers include slugs, sowbugs, earwigs, fungus gnats, and ants.
The easiest way to remove leaf-dwelling insects is by gently spraying the leaves with water. (You should do this even if you don’t see insects, just to stay on the safe side. You don’t want to bring pests indoors.) The spray can gently dislodge insects. If you still see insects after spraying the plant with water, apply an insecticide and keep your newly transplanted outdoor plants away from all indoor plants. Insects can find comfortable accommodations in houseplants.
For soil-dwellers, flick them off with your fingers. If you still see insects, apply insecticide on the soil surface and around the pot’s drainage hole.
Bringing Them Back Outside
Once temperatures remain above 60 degrees Fahrenheit at night in the spring, transition your potted plants outdoors. This should be done over three-to-five days. Start by placing the plants next to your house in a somewhat shaded space and gradually move them to brighter areas in your yard.