The popular geraniums or geraniums are grown by many Czech gardeners. There are currently over 300 species of geraniums of various colours and sizes, both annual and perennial plants, and we usually have semi-shrubs or shrubs in our gardens. The native South African plant is doing well here, but you should still give it special care for the winter. Especially if you grow the plants on a balcony.
Pelargoniums are thermophilic
Almost all pelargonium cultivars are thermophilic from their native Africa, and they don’t mind the Czech winter. They are likely to die on your balcony, even if the coming winter is unusually mild for Czech conditions. Most geranium species are irreversibly damaged by temperatures of around -3 °C, and night temperatures drop below this for most of the winter. If you don’t want to lose your geraniums, you will have to winter them somewhere inside. And you will need to prepare suitable conditions for them.
Transplanting is generally beneficial
Transplanting has another great advantage – if you do it right, it will prolong the life of your plants. You probably find that even relatively young geraniums seem to lose their vigour after a few years, their shoots and flowers become smaller and smaller, and the flowers appear to be fading. Regular repotting can revive them.
How to overwinter geraniums
For overwintered plants, choose a bright but cool room. For example, unheated conservatories are best, but these are not very common in the Czech Republic. A substitute for this is, for example, wintering inside a cottage or chalet if you can leave the heating on slightly. The ideal temperature for overwintered geraniums is 5-10 °C and they need at least 5 hours of natural daylight a day. When repotting, it is also a good idea to prune pelargoniums:
- Trim all shoots to a length of 15-20 cm
- Remove yellowing leaves and dead flowers
- Treat the roses with flower wound emulsion