Judas trees (Cercis) - many enthusiasts refer to the trees or shrubs, which grow up to six meters and larger, as love or heart trees because of the shape of their leaves - are real gems. In spring, the plants show lush, mostly pink or white flowers, which - in contrast to many other flowering trees - also sprout from the old wood and from the trunk. In autumn, the Judas tree inspires with a distinctive autumn colour. However, the Judas tree is not hardy or even frost hardy, even if some sellers may claim this.
The hardiness of the Judas tree depends on the age and the variety
Winter hardiness depends on species and variety
The Judas tree should be absolutely frost hardy or hardy, at least that's what many garden and plant shops, and even employees themselves, claim. Experience shows, however, that sensitivity to freezing temperatures depends on the species and variety of Judas tree on the one hand and that no Judas tree is really hardy on the other. Younger specimens in particular need good winter protection, as they only develop relative insensitivity with increasing age. In addition, Judas trees that are advertised as hardy (e.g. the “Forest Pansy” variety) are not suitable for planting out in regions that are extremely cold in winter.
Choosing a suitable location
However, you can mitigate the consequences of a cold winter by choosing a suitable location. Plant the Judas tree in a sunny, wind-protected and warm location, which should be south-facing and close to a house wall. A partially shaded, draughty place, on the other hand, is less suitable, especially for a solitary plant.
Protect the Judas tree in winter
You should protect your Judas tree when there is a threat of sub-zero temperatures of minus 10 degrees Celsius and more, for example by wrapping the trunk and the crown with raffia mats or jute. The root area can be thickly covered with leaves and/or brushwood to protect the shallow roots. Only bark mulch should not be used, as this acidifies the soil.
Overwinter the Judas tree in a frost-free pot
Basically, specimens kept in pots are much more sensitive to frost than Judas trees planted out. You should therefore either pack Judas trees cultivated in pots well and place the pot on a base made of wood or polystyrene (in regions with a warmer climate) or, if you live in an area with harsh winters, overwinter them frost-free at a maximum of 10 degrees Celsius.
tips
In spring in particular, you should watch out for late frosts and cover the crown overnight, otherwise the buds and flowers could freeze.