Geraniums - meaning the summer flowers that are often planted on balconies, not the native cranesbills - are considered particularly sensitive to temperature. This is not surprising, as the lushly flowering plants come from the southeast African desert areas and are therefore used to completely different temperatures than we are used to.
What temperatures can geraniums tolerate?
Geraniums prefer temperatures between 5 and 10 degrees Celsius for overwintering and at least 10 degrees Celsius during the growth phase. Frost and especially night frost damage the plants, so they should be planted out after the ice saints.
Geraniums do not tolerate frost
This also means that geraniums cannot tolerate frost. At best, the temperature should not fall below five to ten degrees Celsius during the growing period, because then the plant will stop growing until it gets warmer again. An exception is overwintering, where the degrees mentioned are optimal - after all, the plant should not sprout prematurely.
Geranium temperature: Frost is particularly damaging at night
However, it doesn't harm the geraniums if the temperatures fall below five degrees Celsius for a short time - provided there is no frost. The plants cannot tolerate night frost in particular, which is why they should only be planted out after the Ice Saints - when cold nights are no longer expected.
Tip
If the weather permits, i.e. H. If outside temperatures are in the double-digit range, you can put your geraniums on the balcony earlier. But then it makes more sense to bring the plants in overnight.
