The Judas trees (Cercis) are deciduous shrubs or trees that can very quickly reach very considerable sizes. The trees, which come from North America, Asia (particularly China) or southern Europe depending on the species, bloom in early spring and often show attractive autumn colors in autumn. Although the Judas tree (which is often offered under the names heart or love tree) is basically quite easy to care for, the beautiful blossom can still fail to materialize for various reasons.
If the Judas tree does not bloom or only blooms a little, this can have various causes
Possible reasons for the lack of flowering
If your Judas tree does not want to bloom, there are various possible causes - apart from an infestation by pests or pathogens. In addition to the ones listed here, it is also possible that your specimen is too damp or even suffers from waterlogging. In this case, it is important to remedy the situation quickly before wilting can develop due to the high humidity.
Unsuitable location
An unsuitable location is often the reason for a lack of flowering. Judas trees - no matter what kind - like sunny, warm and sheltered places, preferably facing south. On the other hand, locations where they only get sun in the morning and/or evening or where the plants are quite drafty are less than optimal - especially if the tree or shrub is to be kept as a solitary plant.
acid soil
Soil conditions can also be a reason for the lack of flowering. Judas trees need a rather dry and calcareous, neutral to slightly alkaline soil. On the other hand, slightly acidic to acidic soils are completely unsuitable, even if some species or varieties of the Judas tree seem to tolerate them - nevertheless, the affected specimens will be more comfortable with an alkaline pH value.
Freezing back in winter/early spring
Contrary to the claims of some garden center employees, Judas trees are only partially hardy and can freeze back, especially during late frosts in early spring. If buds or even blossoms have already developed, they will also freeze and the blossom will fail. Ergo, Judas trees need suitable frost protection and should not be planted in regions with harsh winters.
Incorrect fertilization
Judas trees are legumes that can produce nitrogen themselves with the help of bacteria. For this reason, fertilization with nitrogenous fertilizers (e.g. blue grain, but also compost and horn shavings) should be avoided. Depending on the condition of the soil, you can fertilize with lime, phosphorus and/or potash to promote beautiful flowering.
tips
If you live in a region that is climatically unsuitable for Judas trees, you can fall back on the no less pretty but more robust cake trees (Cercidiphyllum).