Aesculus glabra Sofia - Ohio buckeye

The Aesculus glabra 'Sofia' is a variety of Ohio buckeye tree characterised by its particularly ornamental spring foliage, which is yellow-orange in colour. It is a large deciduous tree that is both charming and robust. Its elegant foliage, similar to that of the horse chestnut tree, is however finer, and it turns a beautiful red colour in autumn. Although adaptable, this tree prefers humus-rich, permeable, and not too dry soils.

The Aesculus glabra 'Sofia' is a horticultural selection derived from the Ohio buckeye, a tree native to the eastern part of North America. The species is found from Pennsylvania to Tennessee and Alabama, and then to Kansas and Texas. The tree, which can become imposing, grows on moist soils, sometimes even flooded for very short periods. All buckeye trees belong to the Sapindaceae family.

The 'Sofia' buckeye tree, which has a moderately fast growth rate, forms a tree that reaches 8 to 10 meters in height with a roughly equivalent spread. A mature specimen will have a rough, cracked, gray-brown bark with corky and spongy growths, emitting a foul smell when cut. Its buds are not resinous, reddish-brown, with keeled scales and velvety edges. The young branches are vigorous and velvety, but quickly become smooth and reddish-brown. They contain a foul-smelling sap. The foliage is deciduous, appearing in spring with a bright yellow-orange colour, turning yellow, orange, and then red in autumn before falling. The leaves are opposite on the branches, palmate, and measure 20 to 35 cm in length. Each leaf is composed of 5 to 7 elliptical to obovate leaflets, 12 to 18 cm long, delicately toothed, and always with the characteristic foul smell of the species. The flowering, without real appeal, takes place in May. The inflorescences are upright panicles called thyrses, measuring 10 to 18 cm in length. Each carries a few yellow to pale yellow or cream-coloured flowers, 2 to 3 cm long, with stamens longer than the petals. The fruits are tough capsules, 3 to 5 cm in diameter, which usually contain 1 or 2 spherical seeds (rarely 3), smooth, 1.5 to 3 cm in diameter, with a large gray scar. The fruits ripen in September-October and are consumed by squirrels.

The Aesculus glabra 'Sofia' is planted in parks and large gardens, preferably in oceanic or continental climates. It is particularly noticeable in spring, when its yellow-orange foliage stands out against the surrounding greenery. Highly resistant to cold, it also tolerates hot and moderately dry summers. This large tree can be successfully planted in cities as it withstands pollution.