When the temperature drops, your geraniums need a frost-free place to crash for the winter. While our living rooms are definitely frost-free, they’re usually way too warm (and let’s be honest, already crowded with our other plant babies!). That’s why the basement is often the go-to spot. Depending on whether your basement has windows or is a dark dungeon, you’ll need to adjust your overwintering strategy.
Bright vs. Dark Overwintering
If you plan on overwintering your geraniums right in their window boxes, they’re going to need some light. On the other hand, if you give them a heavy prune and store them without soil, they actually prefer the dark. A basement can usually handle both scenarios. If you have a window that’s too bright, a simple curtain can dim things down. If it’s too dark for your potted plants, a grow light can work wonders. Just keep in mind the “golden rule” for the basement: aim for 40-50°F (5-10°C). Generally, the more light they get, the warmer they can be. Ultimately, the method you choose usually comes down to how much floor space you have!
Overwintering in Window Boxes
Before that first frost hits, bring your window boxes into a bright basement. Try not to put them directly against the glass, as intense direct sun can be a bit much. Before they settle in, pluck off any flowers, buds, and damaged or yellow leaves. You don’t *have* to prune them back unless you’re short on space. You can skip the fertilizer during the winter, but since the plants still have their foliage, they’ll lose moisture. Make sure to give them a drink of water every now and then.
Pro Tip:
If you’re tight on space, you can prune several geraniums and tuck them together into a single pot filled with a mix of soil and sand. Keep them in a bright spot and keep the soil slightly moist.
Going Soil-Free for the Winter
If you want to overwinter your geraniums without soil, you’ll need to give them a major haircut first. Cut the stems back so only 3 or 4 nodes remain (about 6 inches long). All the “green stuff”—leaves, flowers, and buds—needs to go. Once you’ve shaken the soil off the roots, give the root system a little trim too:
- Thin out the fine feeder roots.
- Shorten the main roots slightly.
- Cut away any damaged or rotting bits.
- Wrap 3 or 4 plants together in newspaper.
- Store them in wooden crates and mist them with water occasionally.
- Alternatively, put the root balls in a plastic bag, tie it shut, and hang them upside down (this method usually requires no extra watering!).
No Basement? No Problem!
Not everyone has a basement, but don’t worry. An unheated sunroom, a cool hallway, or even a frost-free garage can work. In very mild climates, some gardeners even overwinter geraniums outside in a deep pit in the ground. While a warm living room isn’t ideal, it’s not a total lost cause. If you keep them away from the heater and make sure they get plenty of light, they just might make it through to spring!
