Saving geraniums — How to overwinter your geraniums

The season’s first hard frost can be painful for flower gardeners. I cover some flowers with blankets occasionally, but really, it’s more fun to welcome the new season with open arms. It’s easier for me to do that if I’m able to save some of my favorite annual flowers by bringing them inside. Geraniums especially. 

I have a soft spot for geraniums, because they kinda got me hooked on growing houseplants. About 45 years ago,  I had just moved into a sweet little house near the University of Iowa campus I was about to attend. Sitting on the kitchen windowsill was an abandoned geranium plant. Well, a dried-up geranium stem in hardened dirt. I knew nothing about plants. But I watered it. I talked to it. And it grew! It sent out new little leaves and then the stem greened up, and, eventually, it flowered. (I know now that dormant geraniums can be saved, but at the time, it seemed pretty special!)

Anyway, now that fall is approaching, I’ll be gathering up geranium plants to overwinter. If you planted geraniums outside this summer — in pots or in the ground — consider saving them (or at least your favorites) for next year by bringing them indoors. Not only will they bloom for you through the winter, you can put them back outside next spring for another summer of beautiful blossoms. All you need is a sunny window and these simple directions. (This is a plant project that’s so worth the little effort it takes!) 

You have three methods to choose from for saving your geraniums.

This first method is the one I prefer, because it allows the plant to continue to grow and bloom. A couple of years ago I used this method for two dozen geranium plants and had a window full of exuberant blooms mid-winter. 

Method one: Prep your geranium plant for winter indoors

1. The first step is the hardest (for me, anyway!). Cut the plant back. Way back. Leave only about in inch or two of stem and a handful of leaves. 
2. Dig the plant up or take the plant out of its pot and cut off about half of the roots. Cut from the bottom and from the sides.
3. Remove any stems that don’t look perfectly healthy.
4. Check the plant for bugs and remove any you find.
5. Repot the geranium, using fresh potting soil (not garden soil).
6. Water and place in a sunny window — bright, filtered light (say, through a sheer curtain) is best. 
7. Water when the soil starts to dry out, and, once the plant starts growing, fertilize it with a good houseplant fertilizer every month.

Method two: Make new geranium plants from cuttings

Easy peasy. In fact, by propagating cuttings you can create many new geranium plants from just one big plant. Remember to label your geraniums if you have more than one variety. 

1. Cut a 3- to 4-inch section of stem. 
2. Remove the bottom leaves (say, halfway up the stem).
3. Dip the end of each stem in rooting hormone.
4. Place the stems in a container of sand, perlite, or vermiculite. (Stems can share a pot or go solo.)
5. Water (and keep moist but not wet).
6. Place in bright indirect light (a sunny window with filtered light).
7. Keep the plant humid. For extra humidity, you can create an individual greenhouse of sorts by placing a plastic bag over the entire plant and pot. 
8. If necessary, cut the shoots back as the plant grows, to prevent the plant from getting leggy.

Method three: Store your dormant geranium

This method of keeping your geraniums over winter is handy to know if you’re very busy with fall gardening chores (or something else) and don’t have time to repot your geraniums right away. It’s called dormant storage, which means you’re storing the plant (in this case the bare roots) when it’s not growing. Here’s how to do it:

1. Cut the stems of the plant back to about 3 to 4 inches.
2. Dig up the plant (or take it out of its pot).
3. Shake off the soil.
4. Hang plant, with its bare roots, upside down in a cool, dark spot (like a basement) for the winter. (Alternately, you can place them in a paper bag. Leave the bag open and place on a shelf in a cool, dark spot.)
5. A few times over the winter, take the plants down and soak them in water for a couple of hours. Remove any dead stems. Hang them up again in storage.
6. In early April, pot the geraniums, water them well, and place in a sunny window with filtered light. By the time the frost-free date rolls around, they’ll be ready to head outdoors. 

Next spring

Next May (or whenever the danger of frost in your area is past), harden your geraniums — whether overwintered, potted after dormancy, or started anew from cuttings — to the outdoors by placing them outside in the shade. Bring them in at night if the temps are still dipping. Once they’re comfy in the great outdoors again, plant your geraniums outside, or move the pot outside to a sunny spot. (This is also a good time to repot any geraniums that have outgrown their winter pots.) Not only will you save on your flower budget, the geraniums will be a good size to start with!

There are so many beautiful geraniums (over 400 species), including zonal geraniums, ivy geraniums, and scented-leaf geraniums. There are even some that are hardy perennials (and might not need to be brought indoors for survival). My favorite to grow last year was a Mrs. Pollock geranium with variegated leaves (and I wish I had overwintered it!)

Do you have a favorite geranium? Have you overwintered geraniums before? What method did you use?

You might also enjoy: Storing bulbs for winter and  Garden tool care and keeping (which includes off-season storage info).