Aesculus

Horsechestnut, Buckeye
Hippocastanaceae
Deciduous, Shrubs, Trees

Leaves are divided fanwise into large, toothed leaflets. Showy spring flowers, borne at ends of branches in long, dense clusters, attract hummingbirds. In autumn, leathery fruit capsules enclose glossy seeds. Prune established horsechestnuts only to eliminate dead or damaged wood and any awkward-looking branches.

Aesculus californica

Native to dry slopes and canyons below 4,000-ft. elevation in coast ranges and Sierra Nevada foothills. This graceful plant grows 10–20 ft. or taller and spreads 30 ft. or wider, often with multiple trunks. The new foliage is pale apple green; mature leaves have five to seven rich green leaflets. California Buckeye isstriking in spring, when fragrant, cream-colored flower plumes make it look like a giant candelabra. (Unfortunately, the pollen and nectar of this species are poisonous to honeybees.) Big pear-shaped fruits split to reveal shiny brown seeds favored for dried flower arrangements. Seeds sprout freely; seedlings make unusual bonsai subjects.

In the wild, this plant drops its leaves by July, but if given moderate water, it will hold them until fall. After leaf drop,the silvery trunk, branches, and branchlets create an interestingsilhouette.

Aesculus hippocastanum

Native to Europe. Reaching 60 ft. high, with a 40-ft. spread, this bulky, densely foliaged plant gives heavy shade. Invasive roots can break up paved surfaces. Leaves are divided into five to seven toothed, 4–10-in.-long leaflets. Spectacular flower show: ivory blooms with pink markings are borne in 1-ft.-long plumes.

Aesculus pavia

Shrub or tree native to eastern U.S. Bulky, to 12–20 ft. tall, with an irregular rounded crown that is nearly as wide. Glossy deep green leaves with five to seven 3–6-in.-long leaflets. Narrow, erect, 10-in. clusters of bright red or orange-red (rarely yellow) flowers. Best choice for humid climates.

Aesculus x carnea

Hybrid between A. hippocastanum and A. pavia. To 40 ft. high, 30 ft.wide. Round headed, with large dark green leaves, each divided into five leaflets; casts dense shade. Bears hundreds of 8-in. long plumes of soft pink to red flowers.