There are different methods to overwinter scented geraniums (Pelargoniums), based on whether you want to replant them in spring, keep them dormant, or take cuttings.
Generally, there are four easy ways to overwinter a geranium plant — bring it indoors as a houseplant, take cuttings, place it in cool storage, or store bare roots.
Placing scented geraniums in cool storage — whether in a pot or bare root — and taking it indoors to keep it through the winter are the two of the most common overwintering methods that will be the topic of this article.
Minimum Temperature for Geraniums
Pelargoniums are native to South Africa, so it’s not surprising that they aren’t equipped to handle very cold weather, let alone frosty winters.
Scented geraniums are only winter hardy in the U.S. Department of Agriculture plant hardiness zones 10 and 11.
In other zones, overwintering strategies are the only ones keeping them safe from frost damage.
That said, the minimum temperature for geraniums is around 19 degrees Fahrenheit. This doesn’t mean that the plant won’t sustain any damage at this temperature, but that the frost damage may be only superficial.
Normally, you should already consider making overwintering arrangements for your pelargoniums when nighttime temperatures in the fall start dipping below 55 F.
– Placing potted geranium in cool storage
If you’ve chosen the cool storage overwintering method, here’s what you need to do:
- Find a location for your geraniums where it doesn’t dip below freezing (garage, basement, shed, cellar, etc.). It should be an unheated place.
- Cut back the plant by one-third or one-half and remove any damaged or diseased parts
- Water deeply, then place into storage
- Water infrequently throughout winter and check the plant for signs of disease
– Placing bare root geranium in cool storage
Another way to overwinter your scented geranium in cool storage is to store it in an unheated location where temperature doesn’t dip below freezing level just like in the previous example, except this time you’re not storing them in pots or in soil.
Here’s what you need to do:
- Remove the plant from the pot and remove the soil off the roots
- Air dry the plant for a few days, then wrap them in a cardboard box, newspaper or paper and place on a shelf
- Each month, soak the plants in lukewarm water for 1-2 hours
- Allow to dry a bit before returning to storage
You should store the geranium in a dry place, away from moisture that would favor mold. But never allow it to completely dry out. Soaking the plant in water monthly will keep it alive.
Keeping Geraniums Through the Winter
If you don’t have a cool storage which you could use to overwinter your scented geraniums, there’s also the option to keep geraniums as houseplants through the winter.
If they’re potted geraniums, the process is as easy as taking your scented geraniums indoors and adjusting your care regimen so that it helps the plant survive indoors.
If you scented geraniums are in the ground, you can dig them out and repot them. You can even repot your potted geraniums.
You should schedule to move your scented geraniums indoors about 6 weeks before the first frost. Before moving them indoors, however, here are a few things you should do:
- Remove dead or diseased sections and inspect for bugs and pests
- Prune back the plant by one-third or one-half, but leave any buds or blooms if the plant is healthy
- Pick a sunny spot in your home where you can keep your potted scented geraniums, but avoid hot areas
- Water moderately, keeping the soil moist but not wet. Don’t allow it to dry out completely.
- Hold off fertilizing during winter but start again in early spring.
As you can see, there isn’t any difficulty with bringing your scented geraniums indoors for overwintering.
Make sure to thoroughly inspect for pests, so that you don’t cause an infestation that could spread to your other houseplant.
There are insecticides designed to transition plants from outdoors to indoors, so you can give your geraniums a treatment if you notice pests or even as a precaution.
Placing Overwintered Geraniums Outside
The approach to taking geraniums outside after their winter slumber is pretty much the same, with little variation, depending on the overwintering method you’ve chosen.
If you’ve allowed your geraniums to go dormant during the winter, you will need to revive them and acclimate them for the transition to growing outdoors again.
If you’ve placed your geraniums in storage bareroot, they will need potting in moist potting mix. Before you put them in pots, remove roots that are too long and prune the plant, if needed.
Next, you need to reintroduce them to light. You can do this by taking them outside for a couple of hours each day, lengthening the time each day, until you finally leave them outside.
In about 1-2 weeks, you should already see new growths emerging.
Scented geraniums that were kept indoors as houseplants will only require a period of acclimation to outdoor light. Take your geraniums outside, gradually lengthening the time they stay outside.
When taking scented geraniums outdoors again in early spring, I always take them back inside over the night in case there is a late frost that could damage them.
I only leave them outside overnight, if there is no longer a risk of a late frost setting in.
In early spring, I also start my scented geranium fertilizing program either applying a slow-release fertilizer like Job’s Fertilizer Spikes or fertilizing granules from Osmocote.
Because these are slow-release fertilizers, they don’t need repeat applications for months. If I skip the slow-release fertilizer when planting or repotting scented geraniums, I use a water-soluble fertilizer like the one from Miracle-Gro.
There you have it — multiple ways to overwinter scented geraniums, each with their particularities.
I’ve tried all these methods and found that overwintering in cool storage works best for me, although I’m not averse to keeping these plants indoors either.
Whichever method you find most convenient to you should be fine, just remember to adjust your normal plant care schedule to that of caring for scented geraniums in winter.