Winterizing geraniums to avoid winter frost

The balcony geraniums (Pelargonium) are semi-hardy perennials. In other words, they can only stay outside in the winter in the South. Their survival is entirely linked to temperatures, and in this area, it is better to take precautions so as not to have to buy geraniums in the spring. The best solution is therefore to overwinter them so that they are protected from frost. Let’s do a check in.

Are geraniums chilly?

As soon as temperatures drop to 0°C, geraniums cannot survive. This is the reason why these non-hardy plants are usually grown as annuals and replaced with new plants each spring. However, there is a way to keep them for many years:wintering systematic.

Should geraniums be overwintered before the first frosts?

Whether grown in the ground or in planters, balcony geraniums can only stay outdoors in the mildest climates. Everywhere else, it is absolutely necessary to bring them indoors so that they do not have to suffer the winter cold. Winter frosts are very devastating on these plants, which cannot resist them.

In general, we begin to winter the pelargoniums during the month of October because at this time of the year, many regions experience the first frosts. A very early frost which rages at the end of September also requires the wintering of geraniums even if at this time they are still in bloom. It is therefore not so much the month that counts but rather the weather situation which are very different between the South and the North or the East of our country.

It shoulduproot geraniums grown in the ground. They then undergo a little grooming which makes it possible to remove faded leaves, dead leaves and to cut the branches 2 or 3 cm above the collar. You should also check the roots and cut off any that are damaged. To be overwintered, the dug up geraniums can then be placed on newspaperor hanging upside down even replanted in planters.

What are the best overwintering conditions for geraniums?

Wintering pelargoniums is not very complicated. You need a little space in a frost-free, dry and ventilated room.

Wintering temperature of geraniums

They can be wintered in the cellar, garage, attic, in a cold greenhouse or why not in the veranda or in a room of the house provided that the system of heater that is off. For successful overwintering of geraniums, the ambient temperature should be between 7 and 12°C.

If you have a garden shed, it is imperative to start with theisolate so that you can then store your balcony geraniums there to shelter them from winter frosts. Indeed, in this type of room, in the absence of insulation, it is not uncommon for the temperature to be well below 7°C (it can even freeze there in very cold weather) which does not is not suitable for keeping these plants.


Of course, we avoid overwintering our pelargoniums in a blind room. A minimum of light is required. However, there is no need to install a bay window. If you only have the garage and the door does not have a window, a good handyman can easily make some modifications. Just put a small porthole so that overwintering geraniums benefit from daylight.


More than the lack of light, it is the lack of ventilation that can cause problems during wintering. A room that is not ventilated at all represents a universe too confined for plants. There is then a significant risk of fungal diseases which can kill geraniums in a matter of weeks.

If there is no ventilation grille in the room used as a wintering place, care must therefore be taken to open the door and/or window regularly so that the indoor air is renewed and therefore healthier. for plants. This also allows to fight against excess humidity in the room. Let’s not forget that humidity and confinement are at the origin of cryptogamic diseases.

Should geraniums be watered and fertilized during the winter?

We suspect that in winter, when the plants are in vegetative restit’s important to drastically reduce watering. At most, we must water very sparingly if the substrate is completely dry. Be careful, however, not to wait for the plants to die of thirst. If they lack water, this can be seen by the withering of the leaves.

It is useful to program watering every four or five weeksunless the soil in the planters is still very moist because the excess causes the rotting of all parts of plants. Likewise, to avoid rotting of the roots, do not forget to empty the saucers after each watering. The best is also not to put any at all during the winter.

As to fertilizer inputsthey must be stopped throughout the wintering period of the geraniums since they are dormant.

When is the end of wintering for geraniums?

Depending on the climate, it is between mid-April and the end of May that the geraniums can be put back outside. Here again, it is fundamental to wait until there is no more risk of late frosts. After the Saints-de-Glace (May 11, 12 and 13) these risks are generally ruled out.

The winter outing should not happen overnight. It is very useful for geraniums to learn to readapt to the external environment. To do this, we take them out about two hours a day, when the weather is very sunny do not place them in direct sunlight as this could burn them. After taking their breath of fresh air, they must be placed back in the room.

This acclimatization requires 8 to 10 days, after which all the pelargoniums can finally come out of their wintering to be repotted in a brand new, very fertile compost for geraniums, or in the ground. The watering can is also back in service and we will soon be able to start distributing liquid fertilizer.

Leave a Comment