Red horse-chestnut

Tree & Plant Care

More tolerant of dryness than horse-chestnut, but still grows best in a moist soil.
Red horse-chestnut has a taproot which may make planting difficult.

Disease, pests and problems

Large spiny fruits can be messy.
Leaf blotch and mildew are possible problems, but less so on this species than on related species.

Disease, pest and problem resistance

This hybrid is less susceptible to leaf blotch and mildew than European horse-chestnut.

Native geographic location and habitat

This is a hybrid cross between red buckeye (Aesculus pavia) and Common horse-chestnut (Aesculus hippocastanum).

Bark color and texture

Bark is gray-brown, becoming platy as the tree ages.

Leaf or needle arrangement, size, shape, and texture

Palmately compound leaves arranged in pairs (opposite).
Dark green with 5 or sometimes 7 leaflets.
Fall color is yellow-brown.

Flower arrangement, shape, and size

6 to 8 inch long, cone-shaped terminal cluster.
Flower color varies from pink to red.

Fruit, cone, nut, and seed descriptions

Shiny brown nuts in a 1 ½” prickly husk.
Horse-chestnuts are not true chestnuts and should not be eaten.

Cultivars and their differences

Fort McNair red horse-chestnut (Aesculus x carnea ‘Fort McNair’): 30 feet high and wide with a rounded form. Some resistance to leaf blotch. Pink flowers with yellow throats.

Ruby Red Horse-chestnut (Aesculus x carnea ‘Briotii’): 25 to 35 feet high and 25 to 35 feet wide with a compact, rounded shape. Deep red flowers with yellow throats.

Aesculus x carnea (Red horse chestnut)

Botanical name

Aesculus x carnea

Other names

Red horse chestnut


Aesculus Aesculus


A. x carnea – A. x carnea is a rounded to spreading, deciduous tree with palmate leaves divided into five to seven, slightly twisted, oblong to ovate, toothed, dark green leaflets. Conical panicles of red flowers with yellow centres in summer are followed by spiny, pale brown capsules containing glossy, reddish-brown seeds with hard coats.



Tree shape

Broad crowned


Ingestion may cause severe discomfort.

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Red in Summer

Dark-green in Spring; Dark-green in Summer; Reddish-brown in Autumn

How to care

Watch out for

Specific pests

Horse chestnut scale , Leaf mining moths

Specific diseases

Coral spot , Canker , Leaf spot

General care


Pruning group 1 only when dormant.


Though a hybrid, plants generally a true type from seed.

Propagation methods

Grafting, Seed

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Where to grow

Aesculus x carnea (Red horse chestnut) will reach a height of 12m and a spread of 10m after 20-50 years.

Suggested uses

Low Maintenance, Wildlife, Architectural, Specimen tree


Best in deep, fertile, moist but well-drained or well-drained soil in sun or partial shade. Leaves might scorch and dry in hot, dry conditions. Resents transplanting. A large tree only suitable for very large gardens, planted a good distance from any structure.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid, Alkaline, Neutral


Partial Shade, Full Sun


North, South, East, West


Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 8, Zone 7, Zone 6, Zone 5

Defra’s Risk register #1

Plant name

Aesculus x carnea (Red horse chestnut)

Common pest name

Alfalfa dwarf; Anaheim disease; California vine disease; Dwarf disease of alfalfa; Dwarf disease of lucerne; Leaf scald of oleander; Leaf scald of plum; Leaf scorch; Phony disease of peach; Pierce’s disease of grapevine; Variegated chlorosis of citrus

Scientific pest name

Xylella fastidiosa subsp. multiplex



Current status in UK


Likelihood to spread to UK (1 is very low – 5 is very high)

Impact (1 is very low – 5 is very high)

General biosecurity comments

A bacterial disease with a wide host range detected in Corsica. Although EU regulated; there remains some concern about the risk of introduction. This subspecies is known to be able to thrive in cooler climates. Should an outbreak occur; there would be a need for eradication action which would result in environmental and social impacts.

Defra’s Risk register #2

Aesculus x carnea (Red horse chestnut)

Asian longhorn beetle; Starry sky beetle

Anoplophora glabripennis



Recognised threat to a wide range of deciduous tress native to the UK. Already regulated it is a priority for continued surveillance and statutory action. The risk of entry is further mitigated by EU legislation requiring the monitoring of wooden packaging material originating from China.

Defra’s Risk register #3

Aesculus x carnea (Red horse chestnut)

Elm spanworm; Ennomid; white; Linden moth; snow-white

Ennomos subsignaria



Polyphagous moth pest which defoliates deciduous trees and; with repeated infestation; can cause tree death. Present in North America and current import requirements do not fully mitigate the risk of introduction. A PRA will help to assess the level of risk more fully.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read “Don’t risk it” advice here

Suspected outbreak?

Date updated: 7th March 2019 For more information visit:

Yellowhorn and Red Horse Chestnut

Posted in Gardening Tips on May 28 2014, by Sonia Uyterhoeven

Sonia Uyterhoeven is the NYBG’s Gardener for Public Education.

Flowers of Aesculus × carnea ‘Briotii’

When I was a kid, I used to collect buckeyes or horse chestnuts, shine them and keep them in my pocket for good luck. The large, shiny nuts were a perfect treasure for a kid, and there is a centuries-old tradition that a buckeye in your pocket is a sign that good luck is on its way. The nickname “buckeye” comes from the Native Americans who thought the nut resembled a deer’s eye. My mother went to college in Ohio and my grandparents were from western Pennsylvania, so the common name buckeye was used in my household instead of horse chestnut.

Horse chestnuts are delightful in autumn, when the large nuts litter the ground beneath the trees after the prickly, globe-like husks split open to reveal the treasure inside. Equally intoxicating are the statuesque flowers of the horse chestnut in spring. These great spires of red, pink, or white flowers appear in late spring and liven up the landscape.
Recently, I was admiring a beautiful hybrid red horse chestnut called ‘Briotii’ (Aesculus × carnea ‘Briotii’). The 10-inch flower panicles on this horse chestnut are a rosy red with a yellow eye. ‘Briotii’ is a hybrid between the red buckeye (Aesculus pavia) and the European horse chestnut (Aesculus hippocastanum). It is a compact tree reaching somewhere in the range of 25 to 35 feet tall.

‘Briotii’ has dark green, palmate compound leaves that generally look good late into the season. Many horse chestnuts are susceptible to leaf scorch (burned margins of leaves from dryness), leaf blotch (fungal), and powdery mildew. ‘Briotii’ has a better resistance to fungal problems than its parents. As with all horse chestnuts, while it loves full sun, it is best to avoid planting this tree in a hot, dry location.

Xanthoceras sorbifolium

In the vicinity of ‘Briotii’, I spotted yellowhorn or the Chinese flowering chestnut (Xanthoceras sorbifolium). Our specimen is more the size of a tall flowering shrub than a small tree. Yellowhorn can be grown as a multi-stemmed shrub that will reach around 10 feet tall or a small flowering tree that can grow to 20 feet. The leaves are pinnate compound arranged in a feather-like manner along the stem.

The flowers appear in May, just before the leaves unfurl. Clusters of white flowers are held on 9-inch racemes. The 5-petaled flowers look like stars. At the base of the pristine white petals are luscious yellow centers that morph to red as they age. Round or pear-shaped fruit follow the flowers, containing pea-sized, purplish-brown seeds.

While the Chinese yellowhorn and the European and American horse chestnut are closely related, there are important differences. Once established, the yellowhorn is fairly drought resistant. The seeds in its funny fruits are also edible and used in Chinese cooking, whereas the buckeye or the horse chestnut is inedible and contains a poisonous alkaloid. What they have in common, however, is extraordinarily interesting: a beautiful spring bloom.

Xanthoceras sorbifolium image courtesy of Wikimedia Commons.

The Red Horse Chestnut Tree

Spring passes by so quickly. Only a little while ago I was looking out at the March ice and wistfully writing about the redbud tree, fervently wishing it would finally awaken in crimson blooms. Now most of the glorious trees of spring have bloomed and their flowers have already fallen. The cherry blossoms have come and gone. Summer is on its way with its roses, lilies, and foxgloves, but the trees have largely finished their majestic yearly display. However “largely” does not mean entirely. Walking around my neighborhood this week I have noticed many beautiful shade trees covered with fountaining red blossoms. Since New York City has been busily planting new specimens of every sort of tree, quite a few of these pretty mystery trees are still wearing plastic labels from the nursery (sometimes it is easy to practice dendrology in the city!). It turns out this lovely tree goes by the unlovely common name “red horse chestnut.”

A Red Horse Chestnut Tree (Aseculus x carnea) in Ditmas Park, Brooklyn

The red horse chestnut tree is not a chestnut tree at all: its name is due to the fact that the horse chestnuts and buckeyes (which comprise the Aesculus family) were once erroneously believed to be related to true chestnuts. The name Aesculus means “edible nuts”, but this name too is a misnomer: the nuts are slightly poisonous, containing alkaloid saponins and glucosides. In fact the red horse chestnut tree I noticed on my way to work this morning isn’t even a naturally occurring species of tree. It is a cultivar between Aesculus hippocastanum, the common horse chestnut tree of Europe, and Aesculus pavia, the red buckeye or firecracker plant—a showy native shrub of the American south.

A Horse Chestnut Tree (Aesculus hippocastanum)

The Germans have long been fans of Aesculus pavia, the common horse chestnut tree, a large beautiful tree with spreading boughs and big white blossoms which appear in late spring. In Bavaria the horse chestnut tree was planted above the underground storage caves and cellars where lagers were stored. Brewers and beer enthusiasts once cut ice from ponds and rivers and kept it in these insulated shaded cells to cool the beer during summer (in fact lager means storage in German). It is believed that Germans first hybridized their mighty horse chestnuts with the ornamental American buckeye shrubs to obtain a cultivar with the best aspects of both–presumably so the beer gardens would be even more pleasant in May thus making lager drinking even more delightful. The first red horse chestnut trees seem to have appeared in Germany around 1820.

The Bavarian Beergarden (Otto Piltz, 1875)

Whatever the case, the red horse chestnut trees in my new neighborhood are certainly very beautiful right now. I hope you have noticed that this miniature essay about horse chestnuts is really an elegy to this year’s fading spring. It was a very lovely season and you only get to enjoy four score or so springs in your life (give or take a few dozen). It is the merry month of May and summer is coming. Now it is time to go outside and sit beneath the horse chestnut trees of your garden and enjoy life with your friends and family.

Genieße das Leben ständig!
Du bist länger tot als lebendig!

(Constantly enjoy life!
You’re longer dead than alive!)

Flowers of the Red Horsechestnut Tree

Aesculus x carnea ‘BRIOTII’

Red horse chestnut is a fantastic tree which is usually planted in large gardens and parks, and as a street tree. Although, this hybrid grows a little slower (30 cm a year) making some 6x4m when 20 years old.
Briotti is a popular variety with big, upright panicles of deep pink flowers with a distinct yellow throat, and blooms in May for nearly a month. The flowers sit in the tree like candles on a Christmas tree. Fruits are well-known chestnuts, hidden in spiny capsules.
Glossy leaves are palmate, dark green and fortunately fully or at least more resistant to chestnut leaf minor (cameraria ohridella), i.e. insect which starts eating the leaves of the parent species beginning of summer and by the end of August all leaves are rusty brown and dead. Pruning is recommended if you want to keep it smaller, do so at the end of winter.
The crown is pyramidal when young, changing to somewhat rounded with age, more compact than its parent, casting a deep shade. This chestnut likes deep and fertile soil but will grow almost anywhere, even in slightly chalky soil. Fully hardy to about -29°C (USDA zone 5) but is expected to cope with lower temperatures, too.
Last update 20-01-2008.

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