Aesculus x bushii - Bush's Horse Chestnut

Aesculus x bushii is a hybrid Chestnut tree resulting from the cross-breeding between Aesculus glabra and A. pavia, two American Chestnuts. It is a deciduous tree with moderate growth, commonly planted in the USA but relatively unknown in Europe. Its main qualities are its colourful and nectar-rich spring flowering and its dense palmate foliage that changes colour in autumn. In the garden, it can be used as a shade tree or in a large informal hedge.

The Bush Chestnut belongs to the Sapindaceae family, formerly known as the Hippocastanaceae family. Under the name Aesculus x bushii, slightly different forms can be found depending on their exact lineage. The differences mainly concern the colour of the flowers, which can be more or less yellow, pink, or red, as well as the habit of the tree, which can be more or less broad. This Chestnut tree forms a trunk topped with a more or less rounded crown. Eventually, it reaches a height of 6 to 8 metres (sometimes 9 metres) with a spread of 5 metres. The growing conditions, particularly the soil fertility and moisture, significantly influence its growth. In winter, its branches bear small smooth, non-sticky buds. The leaves are bright green, compound, palmate, with 5 wide leaflets. In autumn, they turn yellow and then fall to the ground. Flowering occurs between May and late June, depending on the climate. It takes the form of flowers grouped in upright panicles. Flowers of different colours can appear in the same inflorescence, but most often they transition from yellow to pink and then red. They attract bees and other pollinators. After pollination, fruits are formed. The fruit is a more or less spiny tough capsule containing one or two seeds. The seed is toxic if ingested.

Aesculus x bushii can be used as a standalone specimen, or accompanied by large shrubs or other small trees. For example, with Flowering Dogwoods, which are interesting for their beautiful June flowering and autumn colours. Also, with purple-leaved beech trees like 'Purple Fountain' or 'Dawyck Purple'. Or even with Amelanchier canadensis (Canadian Serviceberry), covered with white flowers in spring and with colourful autumn foliage.