Horse Chestnut Tree Profile

Horse Chestnut Tree in Spring

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A large tree known for its cone-like, showy flowers that bloom in May, the horse chestnut tree is native to mixed forests in South Eastern Europe, and is widely cultivated along streets and in parks and other outdoor spaces. The tree's large, upright clusters of white flowers bloom in late spring and can be five to 12 inches tall. They are followed up by spiny green seedpods from mid-summer through fall. Along with their beautiful flowers and seedpods, the horse chestnut tree also exhibits an interesting bark with twisted limbs.

The non-native tree can be a bit messy and offers little in the way of vibrant fall foliage, but it makes an excellent choice to line streets or provide some shade from the sun. Considered both a shade and an ornamental tree, the horse chestnut features a lush, spreading canopy that's more than capable of blocking sunlight while adding both visual interest and beauty to landscaping.

Botanical Name Aesculus hippocastanum
Common Name Horse chestnut tree
Plant Type Deciduous tree
Mature Size 50-75 feet high, 40-70 feet wide
Sun Exposure Full sun, part sun
Soil Type Moist, well-drained light, medium, and heavy soils
Soil pH 4.5-6.5
Bloom Time May
Flower Color White
Hardiness Zones 4-7
Native Area Greece, Albania, Bulgaria

How to Grow the Horse Chestnut Tree

A deciduous tree, the horse chestnut is a fairly easy tree to grow, though some species can be prone to leaf diseases, Japanese beetles, and scale insects. Its foliage also tends to scorch and deteriorate in dry soil.

The horse chestnut tree will lose its leaves seasonally. The fruit of the tree is a moderately poisonous seed (the horse chestnut), and can be found inside a prickly husk. The seed is a spiny fruit that's about two inches in diameter and contains one or two blackish, nut-like seeds.

The oblong flower clusters feature a blotch of color at the base which starts yellow and ends as more of a reddish color. The tree itself grows at a medium rate, and planters can expect height increases of approximately 13 to 24 inches per year. As it matures, the tree develops an exfoliating bark, with its outer bark peeling away to reveal orange bark underneath.

Light

This tree will thrive in both full sun and partial shade. It prefers a minimum of four hours of direct, unfiltered sunlight every day.

Soil

Tolerant to an array of soils, the horse chestnut will grow in acidic, moist, loamy, sandy, and silty loam soils--however, the soil should always be kept moist and well-drained.

Water

These trees do not tolerate excessively dry conditions, and will grow best if the soil is kept moist. You'll want to water thoroughly after planting, and then be sure to give the new plant a thorough soaking once a week during summer (unless rainfall is plentiful).

Temperature and Humidity

The horse chestnut tree will only bloom in early to mid-May. Young trees can be protected in winter with a commercial grade tree wrap, which is recommended at least for the first two or three years or growth.

Fertilizer

Newly planted horse chestnut trees respond quite well to fertilizer. Granular, liquid, or stake-type fertilizers can be used. Organic fertilizers, such as manure, can also produce desirable results.

Propagating

Like many trees, propagating horse chestnut trees will require time and patience. It can be accomplished either by seed or through cuttings. To collect the seeds, it's best to wait until they have naturally fallen from the tree to ensure that the seeds are fully mature and viable. You'll also want to choose seeds that are free from cracks and holes, or any other signs of insect damage. When handling horse chestnut seeds, be sure to wear gloves and limit exposure as much as possible, as the seed contains toxins that could irritate skin.

Some Varieties of Horse Chestnut Trees

  • Baumann's Horse Chestnut: Produces double white blooms, no nuts
  • Red Horse Chestnut: Possibly native to Germany, shorter than the common horse chestnut

Pruning

The trees should be pruned either in the early spring before the sap starts to flow or in the fall after the leaves have dropped. Low branches should be removed, as well as crowded or crossing branches. As the tree matures, pruning every three to five years will help keep it in optimal shape.