table of contents
- Ball trumpet tree: growth per year
- Ideal growing conditions
- Ball trumpet tree does not grow
- frequently asked Questions
The ball trumpet tree (Catalpa bignonioides 'Nana') is an attractive eye-catcher even in small gardens with its large, heart-shaped leaves. The spherical trumpet tree, also known as the dwarf trumpet tree, grows slowly, in contrast to its large relative.
In a nutshell
- grows slowly: only 20 to 30 centimeters / year
- less if the conditions are less than optimal
- Water regularly when it is dry
- up to seven meters high
- up to seven meters wide
Ball trumpet tree: growth per year
As a ball trumpet tree, only the variety 'Nana' is called, which, in contrast to the up to 15 meters high original species Catalpa bignonioides, remains significantly smaller and also shows slower growth lays.
- Growth per year: 20 to 30 centimeters under optimal conditions
- maximum height: four to seven meters
- maximum spread: four to seven meters
If the growth conditions are not very favorable during the spring and summer months, the annual growth will be lower or may even stagnate. The crown only grows spherically in the first few years, in older specimens it develops strongly in width. This is why older spherical trumpet trees are often as wide as they are tall - this growth behavior should be taken into account when choosing a location. Otherwise it can happen that the trees do not have enough space after a few years.
Tip: To keep the ball trumpet tree small, you can also cultivate it in a tub. Here the root growth remains limited, so that the shoot growth is also reduced.
Ideal growing conditions
So that the ball trumpet tree does not stagnate in its growth, it needs optimal conditions:
- sunny to semi-sunny location
- sheltered, warm place
- moist and nutrient-rich soil
- loose, permeable soil
- no waterlogging
Specimens kept in pots need as much space as possible for their roots and should be watered and fertilized regularly. The substrate must not dry out, and a lack of nutrients is also fatal for healthy growth. So that the potting soil is moist, but not wet (this promotes root rot), drainage and a drainage facility for excess irrigation water should not be missing.
Tip: Also in contrast to the original species, the small spherical trumpet tree is a little more sensitive to the cold, which is why winter protection should not be missing during the cold season.
Ball trumpet tree does not grow
If the ball trumpet tree doesn't really want to grow or seems even to stand still in its growth, either the conditions are not optimal or the weather is not suitable. In hot, dry years, for example, hardly any new shoots seem to develop. Additional watering and fertilization of planted specimens can help to stimulate growth:
- Keep the root area constantly moist
- three times a year with Horn shavings fertilize
- also suitable complete fertilizer for woody plants
- first fertilization in April
- last fertilization at the end of July
With an appropriate provision, the desired shoot growth can still be achieved despite an unsuitable climate. If, on the other hand, the less than ideal location is the cause, the only thing that will help is transplanting the tree.
Tip: Catalpa is not only characterized by slow growth, but also by the late shoots of leaves. The leaves often do not develop until mid to late May and need to be protected from late frosts.
frequently asked Questions
The trumpet tree (Catalpa bignonioides) has its home in the southeastern United States, where the up to 15 meter high trees grow along rivers in humus and mineral-rich, moist soils. The ball trumpet tree, on the other hand, is a clearly smaller variety of the original species due to breeding and refinement, but which does not develop flowers or fruits.
Basically, the ball trumpet tree can be pruned back and sprouts again even with strong prunings, provided that this is done above the grafting point. However, it is not a good idea to try to keep trees small by pruning - pruning always leads to stronger growth. In particular, the branches should not be shortened, as they then sprout again like a broom and thus impair the natural, harmonious appearance of the tree. It is therefore advisable to choose trees that match the available space.
If you rub the delicate green leaves of the trumpet tree between your fingers, they give off a strong smell. The scent is due to a mixture of catalpin, catalposid and other related chemicals that is typical of the species. They are considered to be only slightly poisonous and are therefore harmless to humans and animals. But the strong smell keeps mosquitoes away, so that the dwarf trumpet tree can serve as a natural mosquito repellent.
