Care of Petunias During Winter Cut the petunias back to about 2 inches 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.Click to see full answer. Also, can I bring my petunias in for the winter?Petunias, though, are actually perennials. In year-round warm climates, they survive and sometimes bloom throughout the winter. If you want your petunias to grow back in the spring, store them indoors during the winter.Similarly, should petunias be cut back? Cutting back petunia plants is not hard. You need to clip a few stems every week. Start early, even if this means you must trim off stems that have attractive flowers on them. Whenever your petunia stems are eight inches long or longer, begin the pruning schedule. Beside this, what to do with petunias at the end of the season? Although they do tolerate heat, petunias sometimes slow down their blooming towards the end of the summer. Cut the stems back to a leaf node and make sure the petunias have enough water to keep the soil moist.Can petunias reseed themselves?Petunias are members of the Solanaceae family, which also includes other familiar plants such as tomatoes, peppers and Nicotiana. If left to their own devices, they may reseed themselves, but the flowers will be a different color from those of the parent plants.