Since petunias are relatively easy to propagate and therefore rather inexpensive, they are usually bought as young plants every year, although overwintering would also be quite possible. However, the effort of regular care in the winter quarters is only worth it to a limited extent, as petunias can be easily grown yourself.
How to propagate petunias?
Petunias can be propagated by seeds or cuttings. Sow seeds from ripe seed capsules on the windowsill from February, while cuttings are cut around 20 cm long and placed in glasses of water until roots emerge.
Grow your own petunia from seeds
If you have petunias in your garden or on your balcony, you can leave some of the wilted flowers on the plants until they have formed ripe seed capsules. Remove the seeds from these capsules and store them in a dark, dry place so that you can use them to grow on the windowsill from February. The following environmental factors should be observed:
- Temperatures around 20 degrees Celsius during the germination phase
- sufficiently bright, but no direct sunlight
- as high humidity as possible (sometimes cover the planters with glass or foil)
In addition, you should not cover the fine seeds with substrate (€6.00 on Amazon) as they are light germinators.
Be careful when planting young petunias
As soon as the second pair of leaves has formed on the home-grown petunias, the young plants should be pricked out and separated to a distance of a few centimeters. Now you should also make sure that the growing substrate never completely dries out. Since petunias are very sensitive to frost, the seedlings may only be transplanted into the garden or balcony box after the Ice Saints at the earliest. However, the young plants should first be hardened off gradually by putting them outside for a few days during the day and back into the house at night.
Propagate the petunia through cuttings
Since the hanging varieties of petunia in particular can produce a large number of long shoots if cared for well, propagation via cuttings is also an option. To do this, cut off a side shoot that is approximately 20 centimeters long and remove all but one pair of leaves at the lower end of the shoot with the interface. Place several of these cuttings in a glass of water; some of them will form fine roots within around two weeks. As soon as roots a few centimeters long have formed, the cuttings can be transplanted into the ground.
Tip
When propagated by seeds, new color variations can occur due to the mixture of neighboring petunia varieties. However, you can get “genuine” offshoots when propagated using cuttings.
