Flowering time (month)
Ornamental or utility value
nectar or pollen plant
moderately humid to humid
weakly alkaline to weakly acidic
The trumpet tree (Catalpa bignonioides) originates from southeastern North America. It grows there on wet, nutrient-rich alluvial soils along the Mississippi River and other large rivers. The botanical name Catalpa is of Indian origin. The tree gives its name to the trumpet tree family (Bignoniaceae), which also includes the trumpet flower (Campsis radicans).
The medium-sized tree grows very quickly when young – annual shoots of 40 to 50 centimetres in length are not uncommon on good soils. It often forms several stems and in old age a compact, broad-pyramidal and very expansive crown. The tops of the lower branches often hang down like a drag. In old age it reaches a growth height of 10 to 15 meters and a crown width of 8 to 12 meters. The thin bark of the old trunks is light grey to brownish and shows elongated furrows. The trees are comparatively short-lived – after about 100 years they begin to degenerate.
The leaves are heart-shaped and strikingly large – up to 20 centimetres long and almost as broad. They are arranged opposite or vertebrally to three at the branches. When rubbed, they spread an unpleasant smell. Under gardeners, the deciduous trumpet-tree is also called “official-tree” because it sprouts late and its foliage colored yellow-green in the autumn already in the early autumn throws off again. As far as photosynthesis is concerned, he is a real short-time worker.
The white, hermaphroditic bellflowers open at the end of May or beginning of June. They have a dark purple spot inside and a yellow stripe-like pattern. The flowers stand in upright, multi-flowered panicle-like inflorescences.
Flowers and fruits of the trumpet tree (Catalpa bignonioides)
The fertilised flowers of the trumpet tree form bean-shaped fruit capsules up to 35 centimetres long and eight millimetres thick.
Location and soil
The location for the trumpet tree should be sunny to semi-shady and somewhat sheltered from the wind, as the large leaves generate high wind pressure. The trumpet tree does not make high demands on the ground. Although it grows best on moist, fertile clay soils, it can also cope with sandy substrates and tolerates even summer drought quite well. In general, it is even recommended to plant the trumpet tree in humid areas that are not too rich in nutrients, as the shoots do not mature well here until winter. The shoot tips then often freeze back in winter and the wood is more susceptible to breakage during storms.
Planting and care
The deciduous trumpet tree can be planted all year round as a container plant. Bare-root specimens are planted in autumn or spring. Special care measures are not required. The root area should be mulched to keep the moisture in the soil. You can do without regular composting or fertilizing. In winter you should shade the trunks of young trees with smooth bark or apply a white coat. They are very susceptible to frost cracks during frost and strong winter sun.
Regular pruning or contour pruning is not necessary with the trumpet tree. The shortening of the main shoot and the side branches should even be avoided as far as possible with young plants, because the attachment points of the newly sprouting side branches or shoot extensions are quite vulnerable to breakage. An occasional radical pruning of the crown branches is only recommended for the spherical shape ‘Nana’ if the crown becomes too wide and sweeping.
Use in the garden
The trumpet tree is an excellent house tree, if you have the appropriate space in the garden, and should be given a single place because of its monumental effect. Under the expansive, shady crown, a cool summer seating area is almost inevitable. The fleshy, heart-shaped root system of the trumpet tree can be well planted with fungi, ferns and other shade plants.
Planting partner for the trumpet tree in the our store-Shop
Ball trumpet tree (Catalpa bignonioides ‘Nana’): The ball shape of the trumpet tree is very popular as a house tree. As a young tree it forms a round and very dense, later broad-oval crown. The tree grows four to six metres high and wide, but does not produce any flowers or fruit.
Gold trumpet tree (C. bignonioides ‘Aurea’): The yellow-leaved variant, with a height of eight to ten metres and a width of five to eight metres, is somewhat smaller than the wild species. Like the spherical trumpet tree, the gold-trumpet tree is also usually offered as a crown graft on high trunks of the wild species.Red-leaved trumpet tree (C. x erubescens ‘Purpurea’): This is a red-leaved hybrid between C. bignonioides and C. ovata. The leaves are clearly smaller than those of C. bignonioides and slightly trilobate. They sprout black-red and turn green during the summer. Especially the white blossoms show to advantage in front of the reddish leaves, still in June. With a height of eight to ten metres and a width of up to eight metres, the hybrid remains smaller than the wild species.
The wild form of the trumpet tree can be sown relatively easily. The seed should be harvested from older trees and be well matured. It is dried over the winter and sown in spring in the field or in the seed tray. The soil should be sandy, humic and not too nutritious. It is important that it has already warmed up well, otherwise the seeds will not run up or only poorly. The seedlings are 30 to 50 centimetres high in the first year and the varieties are usually propagated by grafting. Either by the so-called winter hand refinement by copulation on bare-root seedlings of the wild species or as high trunk refinement on planted high trunks. Okulation in summer is also frequently practiced. All finishing methods have a very high success rate.
Diseases and pests
The trumpet tree is somewhat susceptible to the Verticillium wilt. The fungus spreads with its mycelium in the pathways and prevents the water supply of individual branches, whereupon these suddenly wither and die. The disease occurs mainly on unfavourable soils and is not curable. However, it can sometimes be stopped in young plants by transplanting the trees to another site with sandy, permeable soil. Occasionally, powdery mildew also occurs on the leaves. Pests avoid the trumpet tree as far as possible. Only voles can become a problem because they like to eat the fleshy roots of the plant.
Things to know
In North America, the trumpet tree also has a certain importance as a forest tree. Its beautifully grained wood is often used in furniture construction, for veneers and as parquet. In addition, it is one of the most durable woods in the temperate zone and rots only very slowly even when in constant contact with the ground. All plant parts except the seeds contain the slightly poisonous Catalpin.
I am Don Burke, one of the authors at My Garden Guide. I am a horticulturist that cultivates, grows, and cares for plants, ranging from shrubs and fruits to flowers. I do it in my own garden and in my nursery. I show you how to take care of your garden and how to perform garden landscaping in an easy way, step by step.I am originally from Sydney and I wrote in local magazines. Later on, I have decided, more than two decades ago, to create my own blog. My area of specialization is related to orchid care, succulent care, and the study of the substrate and the soil. Therefore, you will see many articles dedicated to these disciplines. I also provide advice about how to improve the landscape design of your garden.