Aesculus glabra Herkenrode - Ohio buckeye

Aesculus glabra 'Herkenrode' is a variety of Ohio buckeye tree that is interesting for its moderate growth and vibrant autumn colours. This deciduous tree has a short trunk and a naturally rounded crown, well-branched and regular, even without pruning. It also offers a honey-scented spring flowering in shades of yellow, white, and green. Its elegant foliage, finer than that of the chestnut tree, turns reddish-orange from early September. This accommodating buckeye tree will be even more beautiful in the sun and planted in slightly moist humus-bearing soil.

Aesculus glabra 'Herkenrode' is a horticultural selection by Joke Osselaer, Arboretum Wespelaar, registered in Belgium in 2019. It is a seedling obtained in 1994 at the Arboretum Waasland, also in Belgium. Like all buckeye trees, this variety belongs to the Sapindaceae family. It is a relatively slow-growing tree with a rounded habit, reaching about 7 m in all directions at the age of 30. Its leaves measure 16 to 28 cm long and 15 to 20 cm wide, attached to the branches by hairy petioles measuring 7.5 to 15 cm in length. Each leaf is composed of 5 to 6 leaflets measuring 7 to 13 cm long and 2.5 to 4 cm wide. The underside of the leaves is hairy along the veins. The foliage is green from spring until August then changes colour from early September. It displays a mix of cherry red to redcurrant and orange-yellow to orange. These colours can be enjoyed throughout the month before they fall to the ground. The sparse flowers, appear from late April to mid-May depending on the climate. They are yellow-green to chartreuse yellow and white-yellow, carried in upright, cylindrical panicles. Each flower has 4 petals with protruding stamens. The fruits measure up to 3 cm in diameter, they are broadly ovoid and unevenly covered with spines. At maturity, they often have a pinkish hue on a green-yellow base. The trunk bark is rough and fissured when mature.

Aesculus glabra 'Herkenrode' tolerates cold (at least -15°C), rainy or relatively dry and hot summers. Its beautiful autumn colours come back consistently every year, and its naturally rounded branches are interesting even in winter. Its compact size makes it suitable for medium to small gardens. It can be used as a specimen shade tree, or in a grove with other small trees. To accompany it, choose shrubs with remarkable foliage such as Cotinus 'Royal Purple', a Japanese maple 'Atropurpureum', a purple hazelnut, or a European spindle tree 'Red Cascade' for example.