Overwintering Petunias: Growing Petunia Indoors Over Winter

Petunia Plant Growing In A Yellow Container
petunia plants
(Image credit: AtWaG)

Gardeners with a bed full of inexpensive bedding petunias may not find it worthwhile to overwinter petunias, but if you are growing one of the fancy hybrids, they can cost more than $4 for a small pot. This means that you might not be able to use them as freely as you'd like. You can save money by bringing your petunia indoors over winter.

Care of Petunias During Winter

Cut the petunias back to about 2 inches (5 cm.) above the soil and plant them in pots before the first fall frost. Check them over carefully to make sure they aren't infested with insects. If you find insects, treat the plants before bringing them indoors.

Water the plants thoroughly and place them in a cool but above freezing location. Look for a spot in your garage or basement where they'll be out of the way. Check overwintering petunias every three to four weeks. If the soil has dried out, give them just enough water to moisten the soil. Otherwise, leave them undisturbed until spring when you can transplant them back outdoors.

Can You Overwinter a Petunia Plant as Cuttings?

Taking 2 to 3 inch (5-7.5 cm.) cuttings before the first fall frost is a great way to overwinter them. They root readily, even in a glass of plain water; however, the roots become a tangled mess if you put more than one cutting in a glass. If you are rooting several plants, you'll probably want to start them in small pots.

The cuttings root so easily that you won't have to cover them or start them in a greenhouse. Just remove the lower leaves from the cutting and insert them 1.5 to two inches (4 to 5 cm.) into the soil. Keep the soil moist and they will have roots in two or three weeks.

You'll know the cuttings have rooted when a gentle tug doesn't dislodge them. As soon as they root, move them to a sunny window. They won't need fertilizer over winter if you've planted them in a good commercial potting soil. Otherwise, feed them occasionally with liquid houseplant fertilizer and water them often enough to keep the soil lightly moist.

Caution About Patented Plants

Check the plant tag to make sure it isn't a patented plant before taking cuttings. Propagating patented plants by vegetative methods (such as cuttings and divisions) is illegal. It's fine to store the plant over winter or harvest and grow seeds; however, the seeds from fancy petunias don't resemble the parent plants. You'll get a petunia if you plant the seeds, but it will probably be a plain variety.

Jackie Carroll

Jackie Carroll has written over 500 articles for Gardening Know How on a wide range of topics.