Overwintering favorite plants indoors
It's hard to say good-bye to the beautiful summer we've just enjoyed. We'll miss the family vacations and cookouts with friends, and gardeners dread the trip to their compost bins with favorite plants from containers or garden plantings.
But the end of the summer doesn't have to mean certain winter death to some of these flowering friends. We can bring tropical plants and tender perennials indoors and grow them as houseplants until they can return outside next spring.
Good candidates to overwinter indoors include coleus, Cordyline, Euphorbia, geraninum, Hibiscus, Lantana, Mandevilla, New Guinea impatiens, petunia and Rex begonias.
Once nighttime temperatures dip below 50 degrees, it's time to ready plants for their winter home. Lift plants out of the ground or from their containers and repot them. Clean plants by removing all dead or damaged leaves. Deadhead any flowers past their peak.
Carefully inspect them for any signs of insect pests. Look at all parts of the plant including tops and undersides of leaves, stems and areas where stems and leaves meet. Infested plants should be discarded. Spray leaves, top and bottom, with a garden hose to rid the plant of any "hiders." Neem oil can be applied if necessary.
Insects can also be in the soil or on the pot in which plants were growing. Drench the soil to encourage bad bugs to find residence elsewhere. Smaller pots can be dunked in a bucket of water, but do not do this with succulents or other plants that require dry growing conditions. Thoroughly clean pots before bringing them indoors. Don't forget the bottom where spiders often leave their eggs.
If plants were growing in a sunny location, get them ready for less light indoors by moving them to a shaded area in the garden for several days before moving them inside.
Most plants will do best in a sunny window away from heat sources. They need more humidity than typically available in indoor winter air. A room humidifier is an ideal solution but not always feasible; setting pots on water-filled trays of pebbles or misting are less expensive alternatives.
Once plants have been moved inside, they require less watering. Overwatering is one of the quickest ways to kill a plant indoors. Water plants with distilled water only when the soil becomes dry to the touch. Because plants are not actively growing during winter months there is no need to fertilize.
Some plants are easier to overwinter indoors by taking cuttings. Cut the top 4 to 6 inches from coleus stems. Strip all the leaves from the bottom half of stems. Dip the end in rooting hormone and stick cuttings in moistened potting soil or vermiculite.
Place Popsicle sticks around the edges of the pot and cover with Saran wrap. The Popsicle sticks will keep the plastic wrap from touching the cuttings. When you see new growth on the cuttings -- usually in two or three weeks -- you'll know they have rooted.
Or choose the easiest method -- just put your cuttings in a glass of water. Change the water every few days. In a week or so, you will see roots begin to grow at the base of your cuttings. Now they are ready to be planted into potting soil.
Other plants should be cut back. Geraniums, begonias and impatiens all benefit from judicious pruning. Cut them back by half and root prune by about the same amount before repotting and setting them in a sunny window. These plants may not bloom indoors but they'll be ready to put on a show again next year.
The easiest plants to overwinter are those that you just bring in and give them the light conditions they prefer. Crown of Thorns and Tiny Tim Euphorbias will find themselves in a sunny window and several Rex begonias will call my living room home for the winter.
Some plants overwinter best when specific conditions are met. Sweet potato vine prefers cool temperatures and bright light; lantana enjoys cool temperatures but needs lower light conditions; and succulents need bright light and dry soil. Do a little research to find out if you can offer the preferred conditions of the plants you would like to overwinter.
Besides saving money next spring, overwintering plants gives gardeners a chance to keep their thumbs green during cold, gray winter days.
• Diana Stoll is a horticulturist and the garden center manager at The Planter's Palette, 28W571 Roosevelt Road, Winfield. Call (630) 293-1040, ext. 2, or visit planterspalette.com.