Chrysanthemums are popular fall flowers, originally from East Asia. There are now more than 5000 different varieties, of which only the so-called garden chrysanthemums or autumn chrysanthemums are of interest in this country. The following article tells you which varieties are hardy and how to make them winter-proof.
Autumn chrysanthemums are often hardy
Chrysanthemums: hardy or not frost-proof?
The original Asian varieties come from climates that are rather warm to tropical zones and are therefore not hardy here, not even frost-proof. Through targeted breeding and crossbreeding with closely related species such as the Greenland daisy, the first hardy chrysanthemums could be grown in Europe as early as the 19th century. The following rules of thumb apply today with regard to frost hardness:
- Autumn chrysanthemums ("winter asters") are often hardy.
- The later the flowering period, the better the frost hardiness.
- Hybrids are often not hardy.
Chrysanthemum varieties that are not frost-resistant should not be planted out, but cultivated in a bucket if possible. Basically, the autumn flowers are ideal for keeping in buckets.
Winterize chrysanthemums
The first step in winterizing hardy chrysanthemums is to stop all fertilizing. Usually, the heavily consuming perennials are fertilized in the growing season between March and September, with the doses being gradually reduced in preparation for the winter break. The second step concerns the pruning of the faded chrysanthemums: Individual, faded stalks should always be removed to encourage the plant to form new flowers. However, opinions differ as to whether the complete pruning should take place towards the end of the flowering period or only in late summer, shortly before the spring shoots again.
Cut chrysanthemums in autumn or not?
The proponents of spring pruning believe that the plant needs the energy stored in the withered stems to better survive the cold season. The other faction, on the other hand, argues that the same energy hinders hibernation, which is why the plants should be cut back in autumn. Ultimately, both opinions are based on experience, which is why every chrysanthemum gardener should form their own opinion. However, good winter protection is also absolutely necessary for the hardy varieties, for example by covering them with brushwood.
tips
Since potted chrysanthemums should always overwinter in cold house conditions in the house or greenhouse, you can definitely cut them down in preparation for the winter break. The measure then even has the advantage that you do not necessarily have to overwinter the plant in a bright place.