geraniums in a pot by a window

Keeping geraniums

A lot of summer planters will soon be headed for the composter. But if you have geraniums, there’s no need to get rid of them. You can put them in storage until next spring, or even bring them in and enjoy blooms all winter long.

Many of us think of geraniums as our grandmother’s flowers, something that grandma had in pots or in the garden every year. They were almost always bright red, and they bloomed reliably for months without any fuss and with very few insect pests.

Those attributes have kept geraniums in gardens for decades. And while they’re not exactly the most fashionable of flowers, they still have a place and a charm all their own.

We should clarify, though, that those flowers aren’t actually geraniums at all: they are Pelargoniums, a tropical species that dies back at the first frost. True geraniums are often called cranesbills — they are a different species, a low-growing perennial which also blooms reliably for months. But we’ve been calling pelargoniums geraniums for decades now, and it’s unlikely we’ll ever be able to change. Still, to be clear, for the rest of this article we will use both words to refer to pelargoniums.

One of the reasons our grandmothers loved pelargoniums, besides their reliable summer growth, was that they could be kept and regrown the next year. Not only did this save the cost of buying new plants in the spring, it also meant your flowers got a head start on the growing season, bringing you colourful blooms that much sooner.

Old time gardeners even developed a number of different methods to keep geraniums over the winter. The one you choose is entirely up to you — they all work.

Turn them into house plants

If you’ve got a sunny window, this is the simplest method of all. You just need to bring the plants indoors before the first frosts and set them in a window to grow.

OK, you need to do a bit more than that, but not much. If your geraniums are in the ground, dig them up and pot them now… or ideally, about six weeks before the first frost, which for us usually comes in late September.

Whether they are potted or garden-grown, the plants need a hard pruning — a third to a half of the plant should be cut back. Inspect the plants for insects and give them a spray with an organic insecticide — neem oil and dish soap in water is a good choice.

The ideal spot is cool — 12 to 18 degrees is what they like best. Water them lightly through the winter, but don’t fertilize.

In early spring — March or April — start to fertilize occasionally. Start to harden them off in May, and by the time frosts are done, you can put them back outside.

Store in the soil

If you have a cold room or a heated garage, the next couple of methods are even easier.

You’ll need a spot that’s cold but doesn’t freeze. Somewhere dark is ideal.

Cut your plants back by a half to a third, being sure to remove any diseased or moldy parts. Water well, and put the entire pot in the cold room.

Give them a light watering once a month (put a reminder in your calendar!). In mid-April, begin reintroducing them to light and warmth, and watering a bit more. Then by June they’re ready to go outside again.

Bare root storage

This method seems like it shouldn’t work, but it really does.

Dig up the plants to expose the roots. Shake off all the soil and give the plant a hard pruning. Let it dry for a couple of days and then shake off more soil. You want to ensure the plant isn’t wet in storage, or it will get moldy.

Put the plants in cardboard boxes, paper bags, wrap in newspaper or just hang them from hooks in your cold, dark space. The old timers used to say that they plants did better if you hung them upside down, but that advice has largely been discounted.

Once a month, take them out and soak them in warm water for an hour, then let them dry and put them back into storage.

In April, plant them in pots, and start reintroducing them to light and warmth.

No matter what method you choose, you’ll be ready to enjoy some beautiful pelargonium blooms next summer.

Photo by Gemma Evans

Posted in In the Garden.