dahlia.jpgQ: My garden did especially well this year! Is there any way I can bring some of my favorite plants inside to enjoy for a bit longer?

A: As winter is drawing near, it is hard to give up on the plants you nurtured all summer long. When the weather turns colder, it’s time to bring in tropical plants, non-hardy annuals, and tender perennials. Plants such as geraniums, fuchsia, and dahlias may be relocated indoors. No method is totally foolproof, so expect to lose some plants, but you would have lost them anyway if they stayed outside.

Plants can over winter three ways:
1. Treat the plant like a houseplant and keep it in a sunny, warm location,
2. Put the plant in a cool but bright basement or well insulated garage,
3. Store in a dark, cool place where the plant can go dormant.

General preparation
Only bring in the healthiest plants; a weak plant may not survive the transition. Dig up the plant, trying to keep as much of the root system as possible. Plant the transplant in potting soil in a pot with ample room for the roots and adequate drainage. Prune plants to remove any dead or broken foliage. If you want to bring in container plants, collect them as well. To prepare plants for their journey, spray them with a strong blast of water to remove any pests and debris. Spray with insecticidal soap if there are hangers-on. Move the plants to a shady, cool location for a few days, and then bring them indoors. The plant may drop leaves or yellow a bit during the transition. Check plants regularly for dryness and insects, and mist if the humidity is very low.

Pelargoniums (a.k.a. Annual Geraniums)
After spending weeks looking for the perfect red annual geranium, you enjoyed it all summer long. You want that perfect red again next year, so bring the plant inside or take cuttings.

Bringing it inside: Treat geraniums like a houseplant. Prune the plant to 1/2 the original size, place in a pot and keep in a warm and sunny location. Growing a plant in a sunny window is easy, just keep it watered when the soil is dry and turn the pot occasionally to keep the growth even. Geraniums may get leggy growth during the winter, just pinch back to promote fullness. Move the geranium outdoors in the spring when nighttime temperatures are above 50 degrees. Other plants that like this treatment are coleus, marguerite daisies, hibiscus and salvias.

Taking cuttings:
You can take stem cuttings from geraniums, called ‘slips.’ Cut a piece of healthy stem from the tip, approximately four inches in length. Remove the leaves from the bottom two inches of the cutting. In a container, plant the slips in vermiculite or well-drained potting soil. Dip the defoliated end of the slip in a rooting hormone; then plant it two inches deep and water thoroughly. Place the container in a sunny window or under artificial light until the plants are rooted, about three to four weeks. Plant the rooted slips in individual pots and keep them in a well-lighted area. Keep the soil moist and fertilize with a diluted liquid fertilizer when new growth appears, then every four to six weeks.

Fuchsia plants appear delicate but can stand fairly harsh treatment. They will tolerate being shorn and parked away in the corner of a basement or garage for the winter. Leave the plants outside until the first frost. Prune the plant to 1/2 the original size; for hanging baskets, prune to within six to eight inches of the main stem. Do not cut the main stalk. Place the plants in a cool but bright 40 to 50 degree unheated basement or well insulated garage. Water the plants whenever they feel dry. In the spring, move the plant to a warmer, sunnier location. Pinch off the new growth at the tip to promote branching. Feed with a diluted liquid fertilizer when new growth develops and move outdoors when nighttime temperatures reach 50 degrees.

Dahlias are another plant that enjoys indoor accommodations for the winter. In our climate, they are tender perennials that don’t survive the winter. Wait until after a hard frost and cut off the blackened foliage. Dig up the tubers, shake off the soil and set aside to dry in a cool place for a few days. Shake off any remaining soil and place in a well-ventilated container in peat moss. Store the dahlias in a dark, cool area, 40- 50 degrees. Calla lilies, cannas and tuberous begonias can be stored the same way. Check every few weeks to make sure the bulbous roots aren’t too dry. You can mist them, but don’t over water because it will promote rot and fungus. In late spring, plant the dahlias in amended soil about 4-6 inches deep, placing the tuber on its’ side.

Contributed by Valerie Smith, Colorado Master Gardener. Photo courtesy of Colorado State University Extension. For answers to your horticultural questions, until Sep 30, 2009 contact the Master Gardener Help Desk at 520-7684 or CSUmg2@elpasoco.com. Access fact sheets and seasonal information on the El Paso County Horticulture website http://elpasoco.colostate.edu/horticulture/.