Overwintering Geraniums. 4 Tips to Keep them Green and Growing

by Laura Mitran · December 15, 2016

Geraniums (Pelargonium) are perennial plants you can enjoy even during winter with the proper care. We give you 4 easy-to-follow tips on overwintering geraniums to keep them growing in the cold season.

Keep in mind that for successfully overwintering geraniums, you first have to make sure the plants will have good light. This way they will continue to grow, and some will even bloom in winter.

The best places for overwintering geraniums are porches, sun rooms and conservatories. Windowsills are not ideal, but they can make suitable places as well.

Here are 4 easy-to-follow tips on overwintering geraniums:

1. Before bringing your geraniums inside for the winter, examine them. Cut off the dead leaves or dying flowers and look for signs of pelargonium rust. If they have the rust, it’s easily treatable by simply removing the damaged leaves or by using a fungicide you can buy in most gardening shops.

2. Dig up your geraniums and place them in a pot that can comfortably fit their root ball. Water the pot thoroughly and place in a cool, but well lit place. They must be right on the windowsill. If they are only 3 feet away from the window they will get 50% less light.

You can also trim the plants to ensure better growth.

3. Try to keep the air dry where you keep the geraniums, but not their roots. Geraniums don’t go in dormancy, they continue to grow and therefore transpire so they need some moisture. Make sure your geraniums’ roots are moist, but never wet in the winter. Ventilate as much as possible to keep the air dry, ideally using an electric fan heater. If you do not allow the air to move your plants will get moldy and will rot.

4. Overwintering geraniums in the greenhouse leaves you with only keeping them frost free. Set the temperature at 41 degrees Fahrenheit. Rime on the stems means the plant will die.