HARDINESS: Zones 4 to 8
PREFERRED SOIL pH: Acid to neutral
PREFERRED SOIL TYPE: Average
PREFERRED LIGHT: Partial shade
ATTRIBUTES: Early spring foliage, red flowers in late spring; for woodland gardens
SEASON OF INTEREST: Spring through summer
FAVORITES: A. pavia and 'Atrosanguinea', A. californica, A. flava
QUIRKS: Leaves drop in late summer; leaves and fruits are toxic if eaten
GOOD NEIGHBORS: Parrotia, stewartia, white pine, witch hazel
WHERE IT GROWS BEST: Average to wet conditions in partial shade
LONGEVITY: Lives several decades
POTENTIAL PROBLEMS: Susceptible to drought stress and fungal rust leaf disease
SOURCE: Nursery plants
DIMENSIONS: To 25 ft (7.6 m) tall and equally wide
Red Buckeye in the Landscape
The first North American native trees to leaf out in spring, red buckeyes are surprisingly tolerant of late frosts. Since they produce leaves so early, a defense is necessary to protect the foliage from hungry herbivores. Red buckeyes have a toxic sap that deters pests from munching the star-shaped, deeply veined, reddish leaves.
In nature, buckeyes become squat, round-topped, understory trees in moist forests. But in the home landscape they are valued as 25 ft (7.6 m) tall shade trees that produce clusters of red flowers in late spring; hence the common name of red or scarlet buckeye. The variety 'Atrosanguinea' has even deeper red flowers. Clusters of trumpet-shaped flowers attract bees and hummingbirds in large numbers. More curious than beautiful, the clusters of large nuts that develop in late summer eventually drop to the ground. The nuts are toxic if eaten.
Red buckeyes like moist, shady conditions and will even tolerate occasional flooding, but their shallow roots cause them to be easily drought-stressed. Planting in a shady location helps, but red buckeyes will also grow in sun if soil moisture is adequate. In such a location, the trees' dense growth and spectacular red flowers make a terrific display. Red buckeyes are at their best when grown beside stately trees that stand bolt upright.
Other Care-Free Buckeyes
California buckeye (A. californico) is a West Coast native with a multi-stemmed trunk and fragrant white to pink flowers that reaches 20-40 ft (6.1-12.2 m) tall. It is hardy to Zone 7 and tolerates dry, hot conditions. Yellow buckeye (A flora), with yellow flowers and colorful fall foliage, is a larger tree that is native to the Southeast and is hardy to Zone 5.
Growing Red Buckeye
Red buckeyes and their near relatives should be transplanted carefully, keeping the soil ball intact, to avoid damaging roots, in very early spring. Set them at the same depth they occupied in their nursery pots or in the ground, fill the hole around the root ball with soil and water well. The trees often drop their leaves by summer Vend, but if they receive ample moisture through summer they will retain their foliage later into fall. This characteristic can be used to advantage by planting red buckeyes where their early dormancy will reveal the fall colors of companion trees. Buckeyes form a broad, many-branched shape, so prune only to remove dead wood.
The fungal disease rust, which deposits a brownish powdery residue on leaves, occasionally troubles buckeyes. The disease weakens trees and slows their growth but does not kill them. To interrupt the disease cycle, rake up and dispose of fallen leaves.