Why Save Geraniums Over the Winter
Geraniums are everywhere in the spring, so it seems odd it became such a tradition to overwinter geraniums for next season. Perhaps gardeners are such a frugal lot, it’s hard to part with a perfectly good plant. Besides, it’s easy to store your geraniums for the winter. Overwintering geraniums doesn’t even need to take up valuable space under lights or in bright windows. It’s easy, but it’s not always worth it. The longer you keep your geraniums, the woodier the stems get and the less they will flower. They do acquire interesting bonsai type shapes, but if it’s a profusion of bloom you want, you’re better off getting new plants each year. Pruning will increase the blooming somewhat, but you’ll almost always get more flowers from a new plant.
We're talking about zonal geraniums or Pelargonium here, not true geraniums, which are perennials. Zonal geraniums are only hardy to USDA Zone 8 (7 in a good winter). Gardeners in other areas basically have 4 choices of what to do with their geraniums after frost: let them die off as annuals, bring them indoors as houseplants, take cuttings and make more plants, or store them dormant until next spring. Let's take a look at each option.
Grow Geraniums as Annuals
This is the easiest method; grow them for the season and let them die off with the first hard frost. Unless you grow a lot of geraniums, it’s probably just as cost effective to buy a few new ones in the spring as it is to care for them all winter.
Grow Your Geraniums Indoors, as Houseplants, for Winter
Geraniums actually make decent houseplants, if you can provide them with lots of bright light. They like a cool temperature, so even if you keep your thermostat low, they should be happy. However, they’ll start to look gangly and gawky if you don’t provide enough light. A bright west or south facing window or grow lights are crucial. And be careful not to keep the plants too close to a window that gets a draft.
Bring your plants indoors before the first frost. It's best to bring all plants indoors before you have to shut all the windows and turn on the heat. It gives them time to adjust before the drop in humidity that central heating brings.
Check your geraniums closely for signs of insects or disease. Dig and pot up healthy plants and prune them back by about 1/3. It may seem harsh, but it will help them adjust in the long run. Give them a good dose of water when you first bring them in, then allow the soil to dry out between waterings. Geraniums seem to like a little drought stress; it keeps them blooming more frequently.
Keep an eye out for the usual indoor pests like aphids, spider mites and fungus gnats. If your geranium is happy, it will continue to grow and bloom, although not as well as it does outdoors in summer. If it looks like it's struggling to stay alive, consider letting it go dormant until spring. For that, check out Step #5.
Overwinter Your Geraniums as Cuttings
Gardeners either love or hate cuttings. Once you've got the cuttings bug, it's hard to control yourself. You'll eye every plant for its potential of being cut into dozens of plants. Geraniums are easy to root as cuttings. The baby plants take up less space than bringing in the mother plant and they’ll probably have more blooms next season.
Take a look at this step-by-step for making cuttings. In addition, when making cuttings of geraniums, let the cuttings sit overnight, before planting. Allowing the cut end to callus over seems to help the geranium root, rather than rot in the damp soil.
In about 4 - 5 weeks, you should feel some resistance when you gently tug on the cuttings. This tells you the cuttings have rooted and are ready to be potted up and grown as houseplants.
If you are going to overwinter full-size geranium plants, this is the method to use. You basically tuck them away and pull them out again in the spring.
A cool, unheated basement is ideal for storing dormant geraniums. And this is one time when a slightly damp basement is a plus. You want a storage spot where the geraniums will stay cold, but above freezing, where they’ll remain in the dark, and where they won’t dry out completely.
There are 2 approaches, potted or bare root:
01Pot up your geraniums and allow the soil to dry out.
02Cut the plants back by about half.
03Top each plant with an overturned paper bag.
04Store in a cool, dry location.
05Check every few weeks to make sure the plants are not shriveling or drying out completely. If they are, spray them with water or slightly water the root area. Allow the plant to dry off before replacing the paper bag.
How to Overwinter Geraniums by Storing Them Dormant and Bare Root
Bare Root Storage
01Dig your geraniums before the first frost.
02Cut the plants back by about half.
03Shake off as much soil as you can from the roots.
04Either hang the plants in a cool, dark room or place them in paper bags. If you opt for the bags, don’t seal them tightly. You want some air to circulate. If you opt to hang your geraniums, make sure there is enough space between plants for air to circulate around them.
05Check every few weeks to make sure the plants are not shriveling or drying out completely. If they are, spray them with water or slightly dampen the root area. Allow the plant to dry off before replacing in the paper bag.
Reviving Dormant Geraniums - What Happens in the Spring?
It can take a few weeks for your geraniums to wake up in the spring. About 6 weeks before the last expected frost, bring your geraniums back into indirect light. If they’re bare root, pot them up. Bare root plants can also be soaked in water for several hours before potting to re-hydrate the roots.
Give the potted plants a thorough watering and a diluted dose of fertilizer (about half what the package recommends for houseplants) and then let them be as they come out of dormancy. You should start to see them becoming more green and growing new leaves. Don’t move them back outdoors until all danger of frost is past. Good luck!
taken from https://www.thespruce.com/overwintering-geraniums-
till next time, this is Becky Litterer from Becky's Greenhouse, Dougherty Iowa