Winterize your geraniums to save them for next year

There are several ways to save geraniums: store plants as bare roots, pot the plants or take cuttings. Gardeners have success with these methods but there is no assurance that any or all of the plants will survive. Trying to save geraniums is an interesting indoor winter gardening activity/experiment.

Whatever method you choose, make sure you have vigorous healthy plants that are insect and disease free.

The easiest way to overwinter geraniums is to store them as bare roots, but it is also the least successful.

In fall before the first hard frost, dig the plants and gently remove clods of dirt; roots do not need to be clean. Hang the plants upside-down in basement, garage, or dry crawl space where temperatures are 45 to 55 degrees. Once a month soak the roots in water for one hour and re-hang the plant. Plants will lose their leaves but the stems will stay alive for planting again next spring.

After choosing the plants you intend to keep, prune them back by half and remove unattractive/diseased stems. If you have the plants in 6- to 8-inch pots you can leave them in the pots making sure there are no insects lurking in the soil. To avoid soil insects repot the plants in 6- to 8-inch pots using fresh potting soil.

If the plants are in larger pots or in the ground, carefully dig them up and plant in 6- to 8-inch pots as described. Water thoroughly and place under fluorescent lights or in a bright south window so they receive 10 to 12 hours of sunlight a day. Geraniums can tolerate arid conditions. They overwinter best in temperatures from 60 to 70 degrees with infrequent watering. They will become “leggy if they are kept in warmer temperatures.

Taking cuttings

Supplies needed: vermiculite, perlite or sand dampened with water; small planting containers with drain holes at least 2 inches deep; rooting hormone.

1. Before a hard frost take cuttings from your plants. Each cutting should be a thick stem about 4 inches long. Take a few more cutting than needed since some cuttings may not take root.

2. Remove all flowers and buds, except for four leaves from terminal end.

3. Place the cuttings on a surface for 10 to 12 hours so a callous forms on the cut stem. This helps prevent root rot.

4. Place the growing medium into the containers and make holes in medium so rooting hormone remains on cutting when it is planted.

5. Dip the stem into rooting hormone up to the leaves and place into planting hole to just below the leaves. Water thoroughly and place into bright window or under fluorescent lights. Keep growing medium moist but not wet.

Cuttings should take root in four to eight weeks. When rooted, repot into 3- to 4-inch pots and grow under fluorescent lights or bright light until ready to plant in spring.

Q. What can you tell me about rain barrels? I would like to set one up but am afraid it will attract mosquitoes.

A. Rain barrels, once common for collecting rainwater, are again becoming popular. With the growing interest in home gardens and “greening of the environment, rain barrels are an excellent way to collect water that is free of chlorine and fluoride typically added to city water supplies. In addition, using rainwater in urban areas saves on water bills and helps conserve the local water supply.

Once you start collecting rainwater you may be amazed at how much water a one-half inch rainfall drains from your roof. Most rain barrels hold 50 to 60 gallons. One-half inch of rain collected from a 1,000-foot section of roof results in about 312 gallons of water ... enough to fill more than five 55-gallon barrels.

Because of the amount of rain coming off a roof many people choose to install two or more barrels in a series. Rain barrels are available seasonally at many hardware stores and through the Internet. Depending of the size and “bells and whistles most of those barrels cost from $100 to $300. You can also make your own barrel by purchasing the needed components locally or via the Internet. Likewise various sets of directions are available on the Internet.

Any opening to the rain barrel should be covered by fine mesh screen to keep insects, animals and debris from collecting in the barrel. Mosquito Dunks are the solution to keeping the barrel from becoming a mosquito-breeding tank. The dunks are natural control using Bti (Bacillus thuringiensis israelensis,) a bacterium that infects and kills mosquito larvae and close relatives including gnats and black flies. The dunks do not harm other insects, worms, birds and mammals. One dunk treats 100 feet of water for about 30 days.

Mosquito Dunks are available locally at nurseries and hardware stores in packets of six, 12 or 20. The barrels should be drained, dismantled and cleaned before freezing temperatures in the fall.

Ÿ Provided by Mary Boldan, Mary Moisand and Donna Siemro, University of Illinois Extension Master Gardeners. Send questions to Ask a Master Gardener, c/o Friendship Park Conservatory, 395 W. Algonquin Road, Des Plaines, IL 60016, (847) 298-3502 or via e-mail to cookcountymg.com@gmail.com.