"My walnut tree isn't blooming. How can that be?" Entries like this one can be read again and again in forums about walnut trees. In our guide we describe possible causes of the missing (as well as the one-sided) walnut tree blossom in detail. An encouragement to start: In most cases there is something completely harmless, normal behind it.
Walnut trees do not flower until they are at least 15 years old
Potential causes of the lack of flowering
There are essentially two reasons for the lack of flowering:
- the tree is still too young (harmless)
- the tree is frozen (severe)
Walnut tree is still too young
Anyone who has not yet dealt with walnut trees in more detail is probably surprised that there have been no blossoms for several years. In principle, however, there is no reason to worry, because: The first flowering usually occurs at the earliest at the age of ten, more likely even at 15 to 20 years.
Important: This information relates to seedlings. In the case of cultivars, the first flowering usually occurs after four to six years.
Incidentally, the first flowering also goes hand in hand with the first harvest, since the fruit develops from the flowers.
Walnut tree has frozen
The second possible reason why a walnut tree does not bloom (anymore) is frosts, especially late frosts. Check to see if your tree may have frozen. This may be the reason why the tree doesn't sprout - if you're lucky it's only for the one year; if you are unlucky, however, your walnut plant will be so frost damaged that it will no longer live.
Potential causes of unilateral bloom
It is quite possible for young walnut trees to produce only male or only female flowers. This should not confuse or unsettle you.
With increasing age, the one-sidedness usually subsides, so that the male and female flowers appear together and are appropriately distributed.
Note: Without weather-related influences, the female flowers always develop about four weeks after the male flowers.
Weather-related influences are in particular a long, hard winter or a late spring. In such circumstances, the male and female flowers open more or less simultaneously.