Zonal geraniums are usually only grown as annuals, except in USDA Zones 10 and 11 where the mild climate allows them to flourish outdoors all year long. So, come fall, gardeners in Zones below 10 have four options for their beloved plants: 1. Let them die off as annuals, 2. Bring them indoors as houseplants, 3. Propagate new plants from cuttings, and 4. Store them dormant until next spring.
Storing geraniums for the winter doesn’t need to take up valuable space in your home. And it's easy to do, too—though not always worth it. If your garden is full of this flower, pot them up to add beauty to your indoor setting. However, if you only grow a few plants each year, buying new ones in the spring may be just as cost-effective as overwintering.
When to Overwinter Geraniums
The easiest method for growing geraniums annually is to let them die off with the first hard frost and then replace them in the spring. However, you can't wait until it frosts for overwintering. Instead, full plants and clippings must be harvested in the fall while the plant is still blooming and the temperatures are mild. If you harvest too late, the plants may have already entered their die-off phase. And harvesting too early can mean sacrificing peak blooms in your outdoor garden.
- Working time: 1 to 2 hours
- Total time: up to 6 months
- Material cost: under 30 dollars, depending on the method
What You'll Need
- Garden shovel
- Garden trowel
- Gardening gloves
- Garden shears
- Paper grocery bags
- Spray bottle
- Ceramic pots
- Potting soil
- Sterile potting soil
Overwintering Geraniums by Growing Them Indoors
Geraniums make decent winter houseplants if you can provide them with plenty of bright light. A bright west or south-facing window, or grow lights, will assure they won't grow spindly, but make sure to situate the plants away from drafts that might force dormancy.
- Before the first frost, check your geraniums closely for signs of insects or disease.
- Dig up and pot healthy plants and prune them to one-third of their size.
- Water the pots well, and then allow the soil to dry out.
- Bring your plants indoors well before its time to shut all the windows and turn on the heat. This gives the geraniums time to adjust to the drop in humidity that indoor conditions provide.
Overwintering Geraniums as Cuttings
Once you perfect the art of cutting, it's hard to control yourself. Gardeners will often eye every plant for its potential to be transformed into dozens more, making this an economical way to build next year's garden. Plus, geranium clippings take up less space than the mother plant and tend to yield more blooms in subsequent seasons.
- Cut a sizable portion of the plant just above a node during a lull in the blooming cycle.
- On your new cutting, make another cut below a node so that your new plant is 4 to 6 inches long.
- Strip off all of the leaves except for the ones at the tip.
- Let the cutting sit overnight, allowing the cut end to callus over.
- Plant the cutting in damp soil and place it in a bright window.
- Water the cutting whenever the soil feels dry and allow it to root (1 to 2 weeks).
- Grow the new geranium as a houseplant until spring, and then move it outside.
Overwintering Dormant Geraniums
Overwintering full-size geranium plants involve tucking them away and then pulling them out again in the spring. A cool, unheated, slightly damp basement is ideal for storing dormant geraniums in pots.
- Pot up your geraniums before the first frost and allow the soil in the pot to dry out.
- Cut the plants back by approximately half.
- Place an overturned paper bag on top of each plant and store it in the basement.
- Check your geraniums every few weeks to make sure the plants' leaves and stalks are not shriveling. If they show signs of drying, spray them with water or slightly water the root area. Then, allow the plant to dry completely before replacing the paper bag.
Overwintering Dormant and Bare Rooted Geraniums
Another approach to overwintering geraniums involves storing them with bare roots. For this method, hanging the plants, or covering them loosely with a paper bag, works well and eliminates the need for pots. As with any dormant storage, you want to select a spot that keeps the plants cold, dark, and damp, but above freezing.
- Dig up your geraniums before the first frost.
- Cut the plants back by approximately half and shake the soil from the roots.
- Either hang the plants upside down with twine or place them in loose-fitting paper bags. Then, store them in a cool, dark room. If you opt to use bags, make sure not to seal them tightly to allow airflow. If you opt to hang your geraniums, provide enough space between plants for air circulation.
- Check your plants every few weeks. If they are shriveling, spray them with water or slightly dampen the root area. Allow the plants to dry completely before placing them back into the bags.
Tips for Overwintering Geraniums
When growing geraniums indoors, keep an eye out for the usual 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 in its outdoor environment. But if your plant looks like it's struggling, consider letting it go dormant until spring.
The longer you keep your geraniums growing in pots indoors, the woodier the stems become and the less they will flower. So if it's a profusion of blooms you want, you’re better off purchasing new plants as annuals each year.
Working With Dormant Geraniums
About six weeks before the last expected frost, relocate your dormant geraniums to indirect light. If their roots are bare, soak them in water for several hours to rehydrate the roots before potting them up.
Give the potted plants a thorough watering and a diluted dose of fertilizer (about half of the package recommendations), and then let them slowly come out of dormancy. You should start to see new green leaves after a couple of weeks. Move them back outside once the danger of the season's final frost is past.