Catalpa - Growing Guide

Growing Catalpa

The four species of catalpa which we offer are all of Chinese origin although C. speciosa is North American. C. bignonoides, the ‘Indian Bean Tree’, has been grown in the UK since 1726 and is now well established in parks and gardens in the UK. It makes an excellent feature tree in a lawn with its enormous ovate or heart shaped leaves and pyramidical panicles, 8-10in long and wide, of numerous white flowers in mid to late summer. These are tube or bell like with two ridges and two rows of yellow spots. The tube has purple spots in the tube and on its lower side. The fruits are rounded, pencil like, and from 6-15in in length. Hence the ‘bean tree’.

Catalpa fargesii var duclouxii    click for larger image
Catalpa fargesii var duclouxii
Catalpa szechuanica  click for larger image
Catalpa szechuanica
Catalpa x erubescens purpurea  click for larger image
Catalpa x erubescens purpurea

C. bignonoides grows to 25-50ft tall. As a young plant it is disinclined to form a leader or leading shoot. Therefore it is sensible to prune out to a central leader and tie this in to a cane or stake until the tree is around 10ft tall. Then it will establish a clear trunk and can grow away in a spreading fashion with room to walk underneath it.

The other species of catalpa are just as hardy as C. bignonoides but do not grow quite as big or tall. C. fargesii var duclouxii produces root suckers at Caerhays and grows to only 15 or so feet. Its flowers are pinkish and frilly with spotting of brown and red around the throat stained with yellow. The flowers appear in corymbs of seven to fifteen flowers in June. To us it is the most spectacular of the catalpas in flower. The plant at Ventnor Botanics by the hothouse can be the best display in the garden there.

Catalpa bignonioides click for larger image
Catalpa bignonioides
Catalpa bignonioides click for larger image
Catalpa bignonioides
Catalpa bignonioides click for larger image
Catalpa bignonioides
Catalpa bignonioides click for larger image
Catalpa bignonioides

Catalpa come in forms with golden leaves (C. bignonoides ‘Aurea’) and with purple new growth and leaves (C. x erubescens ‘Purpurea’).

Catalpa x erubescens   click for larger image
Catalpa x erubescens 'Purpurea'
Catalpa x erubescens purpurea  click for larger image
Catalpa x erubescens 'Purpurea'
Catalpa x erubescens purpurea  click for larger image
Catalpa x erubescens 'Purpurea'

Catalpa are greedy plants and respond well to root mulching and additional feeding. They need deep loamy soil and an open sunny spot where the wind cannot damage the branches when they are still carrying huge leaves as they do well into autumn.

Catalpa are most easily grown from seed collected from the ripe ‘beans’ in late autumn and sown straight away in an open frame.


Tidying damage on Catalpa - Video Tip


Catalpa duclouxii - Video Tip


Catalpa in July - Video Tip

0:00 - Catalpa bignonioides
3:30 - C. x erubescens
5:17 - x erubescens 'Purpurea'
6:28 - speciosa ‘Pulverulenta’
8:17 - bungei ‘Duclouxii Group’ (stills)

 

 


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