Actually, the trumpet tree (Catalpa bignonioides) applies - please do not confuse this with the similar-sounding angel's trumpet (Brugmansia)! – as quite uncomplicated. However, if the deciduous tree is not cared for properly or in the wrong location, it can develop signs of discomfort, for example by turning its leaves yellow and/or simply dropping them. Unfortunately, the exotic is also quite susceptible to the dreaded verticillium wilt.
Why is my trumpet tree losing leaves?
A trumpet tree may lose leaves if it suffers from nutrient deficiency, drought, or verticillium wilt. Sufficient fertilization and irrigation help against nutrient deficiencies; measures such as pruning and changing locations are recommended for verticillium wilt.
Nutrient deficiency and dryness are common causes
In most cases, the leaf drop is not caused by wilt disease, but simply by a lack of nutrients and/or water. Especially in the hot and dry summer months, it is recommended to water the trumpet tree both in the morning and in the evening. However, you should ensure good drainage - especially for specimens cultivated in pots - because Catalpa cannot tolerate waterlogging either. Regular fertilization is also essential, because the trumpet tree is a heavy feeder.
Avoid chlorosis
Chlorosis - i.e. diseases due to a lack of nutrients - often shows up in yellowish leaves in which the leaf veins are clearly visible. As a rule, the plant in question is missing a certain mineral, often iron. Chlorosis can be treated very well and prevented even better, namely through adequate fertilization. Young trees in particular need good fertilizer, and mature compost has proven particularly useful for planted specimens. For trumpet trees cultivated in pots, however, we recommend good universal fertilizers that are not too rich in nitrogen (€10.00 on Amazon).
Verticillium wilt usually fatal
If whole shoots suddenly die off on apparently he althy trees and leaves dry up and fall off, the so-called wilting disease may be behind it. This is a fungal infection in which the verticillium fungi that live in the soil penetrate the tree's wood via the roots and pathways and block the supply of water and nutrients. No herb has yet grown against this disease. All you can do is take the following measures and hope that you can save the tree:
- Cut all affected plant parts far back into the he althy wood.
- Under no circumstances should you dispose of these in the compost!
- Dig up the trumpet tree and replant it in another, more suitable location.
- Treat the tree with a tonic.
Tip
Fungicides unfortunately don't help at all against verticillium wilt because the fungus sits deep in the wood. You can only prevent an infestation by carefully following the care and planting instructions and also not planting the trumpet tree in a location where the disease has already occurred.
