The common trumpet tree (Catalpa bignonioides), a deciduous deciduous tree with strikingly large leaves, is cultivated primarily for its ornamental value in gardens and parks. In addition to the fresh green, heart-shaped leaves, the trumpet tree also produces large, funnel-shaped flowers - although not always. You can find out why your trumpet tree isn't blooming in the following article.
Why isn't my trumpet tree blooming?
If a trumpet tree does not bloom, it may be due to its age, variety, care, location or excessive nitrogen fertilization. Make sure there is enough water, a sunny location and appropriate fertilization to promote flower formation.
Not every trumpet tree blooms
First of all: Not every trumpet tree produces flowers. Some varieties, especially the globe trumpet tree 'Nana', are even known not to bloom at all, only very rarely and if they do, then only in old age. In general, the common trumpet tree only develops flowers very late: you don't need to expect flower decorations before the fifth to eighth year (which corresponds to an actual age of around eight to ten years).
Incorrect care sometimes prevents flowering
In some cases, however, trumpet trees do not bloom because they do not like the care. Especially if such a tree that is reluctant to bloom is frequently under drought stress, it tends to refuse to bloom. When it comes to water, the trumpet tree is a real mimosa: On the one hand, it needs a regular supply of water and, above all, even moisture - especially if it is grown in a pot - but on the other hand, it also cannot tolerate waterlogging. You can resolve this contradiction by ensuring good drainage (e.g. by adding clay granules (€19.00 on Amazon) and sand to the substrate) and choosing a sufficiently large pot. Water moderately but regularly - the tree must not be left dry.
Does the tree feel comfortable in its location?
Basically, the trumpet tree feels comfortable in a warm, protected and sunny location. On the other hand, if the tree is too shady, only a few or even no flowers will be produced. But a location that is too exposed can also lead to a lack of flowering if the trumpet tree is regularly too dry. The rule of thumb applies: the sunnier and hotter a location, the more water the tree needs. Drying and/or yellowing leaves can be an indication of a lack of water.
Tip
In addition, nitrogen-based fertilization can lead to flower failure, as in this case the tree puts the energy into the development of roots and leaves and into growth. It is best to fertilize the slow-flowering specimen with organic fertilizer such as mature compost. By the way: Manure is also usually rich in growth-promoting nitrogen.