Sizeable, deciduous trees, with smooth sticky buds and large leaves. Aesculus are noted for their prominent, upright, spring flowering clusters and round, spiky green fruits. When mature the fruits split to release shiny brown nuts (conkers) - often collected by children who love to string them and play conker battles.
Family: Sapindaceae (soapberry)
Botanical Name: Aesculus
Common Names: Horse chestnut, buckeye
Foliage: Deciduous, large, palmately-lobed green leaves. Most species provide good autumn colour.
Blossom/Fruit: Large, upright conical flower panicles, often fragrant. Round green fruits appear in September and October.
Horse chestnuts have prickly fruits containing one or more shiny brown nuts (conkers). Buckeyes have smooth fruits.
Flowering Period: Spring.
Soil: Moist but well-drained soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun or partial shade, in any aspect.
Habit: Tall, broad canopy.
Type: Tree or large shrub.
Origin: Europe, Balkans.
Toxicity: Harmful if ingested. Wear gloves and wash hands after handling.
Hardiness: Fully hardy in the UK.
Horse chestnut trees thrive in virtually any soil type as long as it is not waterlogged. Best grown in full sun where they can be allowed to flower freely. Some species will tolerate light shade, especially the smaller shrubby forms.
Aesculus are easy to grow, low maintenance plants, requiring very little care and attention once established.
Pruning is not necessary, except for the removal of dead wood and overcrowded or crossing branches.
Can be affected by horse chestnut scale and leaf-mining moth. Susceptible to coral spot, canker, leaf spot and honey fungus.
Easily propagated from fresh seed (nuts), although a two to three month period of 'cold stratification' is usually required before germination can occur. Named varieties can be propagated by budding or grafting. Smaller, shrubby species can be increased by layering or grafting.
Horse chestnuts vary widely in size, stature, leaf shape and flower colour. Most species produce large, statuesque trees that are really only suitable for very large gardens or a parkland setting. Although, there are a few compact varieties that can be accommodated in smaller spaces.
Aesculus californica (Californian Buckeye) makes an attractive compact tree with a low, wide-topped, roundheaded habit. Height 20 to 30ft. Long, greyish-green leaves. Fragrant white flowers tinged with pink, in June and July.
Aesculus glabra (Ohio Buckeye) makes an attractive middle-sized tree with a much smaller leaf than the common species. Greenish yellow flowers in May and June. Bark of the trunk is fissured.
Aesculus hippocastanum (common or true horse chestnut) is a large tree that produces masses of large white flower panicles. Grows quite quickly and needs a lot of space. A thirsty and hungry plant that is not suitable for growing near buildings. Height to 100ft (30m), spread 50-70ft (15-20m). The double flowered variety 'Pletla', has longer lasting blossom but does not produce fruits.
Aesculus x carnea (red horse chestnut) is often found growing in parks and avenues. Pinky-red flowers from late May until early June, followed by slightly prickly fruit. A smaller, slower growing tree of rounded habit that will eventually reach a height of 35-50ft, spread 25-40ft. Cultivar 'Briotii' is one of the best and most richly coloured forms. For sale at Thompson & Morgan.
Aesculus indica (Indian Chestnut) is a large tree with white flowers flushed with a tinge of pink and yellow. Shiny and slightly folded leaves with good autumn colour.
Aesculus neglecta 'Erythroblastos' is a slow growing tree with new leaves of shrimp pink.
Aesculus octandra (Sweet Buckeye) is a handsome upright tree with yellow flowers in May and June. Height to 40ft.
Aesculus pavia (Red Buckeye) is one of the smaller species forming a small tree or shrub of 13ft (4m). The flowers are a good shade of bright red.
Aesculus parviflora is a medium sized shrub, with white flower spikes that appear later in the season. Good autumn colour. Height 10-13ft (3-4m). For sale at Thompson & Morgan.
Aesculus plantierensis is a hybrid between the common horse-chestnut and A. catnea. It is very like the former in leaf and growth, but is not so vigorous. The flowers are suffused with pink and does not produce fruit.
Aesculus turbinata (Japanese Horse-chestnut) has a stiffer, sturdier slow growing habit and large leaves.