Be careful with the petunias
While some potted plants can withstand a few freezing temperatures for a short time, the petunias and their various subspecies are all very sensitive to frost. Therefore, make sure to protect the plants from any hypothermia, as this usually leads to the death of the entire plants. If you buy new petunias every year as young plants for the balcony, you can simply let the petunias bloom until the first frost and then compost. For attempts at wintering, however, the plants must be brought to winter quarters before the first frost and only rewintered after the ice saints.
- Petunias: poisonous or not?
- Plant petunias in the garden or on the balcony
- How sensitive are petunias to frost?
Hibernate the petunia under suitable conditions
The surfinias, valued as cultivated species of petunia because of their better weather resistance, are also extremely sensitive to frost. However, since surfinias are available in particularly attractive color combinations and, due to their sometimes pronounced self-sterility, cannot be grown from seeds, it is worth wintering in a protected area for these too. In this the following conditions should apply:
- as bright as possible (however no direct sunlight on the plants is necessary)
- Temperatures between 5 and 10 degrees Celsius
- regular maintenance
The comparatively low temperatures for wintering petunias can best be achieved in a tool shed or basement. The plants should be easily accessible, however, as they must not dry out and should be checked regularly for pest infestation.
Preventing difficulties during the winter
When placing in the winter quarters, balcony boxes with petunias should be checked for a possible infestation with aphids so that they cannot spread massively over the winter. The right plant substrate ensures that moderate watering prevents the plants from drying out and still prevents waterlogging and root rot. The shoots of the petunias are shortened to 15 to 20 centimeters in length for wintering. Flower buds are removed in winter so that the plants in their winter quarters are not energetically depleted.
If you do not have the right space to overwinter the non-hardy petunias, you can also collect the seeds in autumn and grow young plants from them yourself on the windowsill from February onwards.