Ruby Red Horse Chestnut Aesculus x carnea

Aesculus x carnea, or Red Horsechestnut, is a deciduous shade tree in the Sapindaceae family (and was formerly listed in the Hippocastanaceae family). It is a hybrid between the larger A. hippocastanum and the smaller A. pavia and probably originated in Europe in 1812. The genus name, Aesculus, comes from the Latin describing an oak that bears edible acorns. The species name, carnea, means flesh colored or deep pink and refers to the color of the flowers. Although this is a hybrid, new plants will come true from seed.

The flowers of the Red Horse Chestnut (pink or red depending on cultivar) are the main attraction of this medium sized tree. After the flowers bloom, they are followed by the seed pods, which can be messy and may be a drawback of this tree in the landscape. However, in the right location such as a large residential lawn, park, city parkway, or large parking median with good drainage, it can be a striking specimen shade tree. Initially, the tree has a pyramidal shape, but after 5 to 7 years, it matures into a dense rounded form. The tree grows best in moist acidic fertile soils, but will tolerate average soils with good drainage. Minimal pruning is required, but if it is pruned, make sure that the bark does not crack with sudden exposure to the sun. Once established, this tree is difficult to transplant due to its large taproot.

Diseases, Insects and Other Plant Problems:

Disease is less of a problem than with most horse chestnuts but it may develop powdery mildew causing early leaf drop. Dry conditions cause leaf scorch and, although it is more drought tolerant than most Aesculus, it does not thrive in drought conditions. Leaf blotch can be a significant problem. Bagworms, Japanese beetles and borers are infrequent but potentially troublesome. In general, this tree has better disease resistance and its foliage is less apt to depreciate as the growing season progresses than is the case with A. hippocastanum