- Mature height
- 15m to 20m
- Mature width
- 10m to 15m
Aesculus hippocastanum, the horse chestnut, is a large deciduous shade tree with a straight trunk and a broad rounded crown. Big palmate leaves of five to seven leaflets build a dense summer canopy. Upright candles of white flowers marked with yellow and pink stand above the foliage in spring, followed by spiny seed cases.
It needs deep, fertile, well drained soil and a cool climate with a proper winter. Full sun to part shade suits it and it is thoroughly frost hardy. Growth is moderate at 30 to 50 centimetres a year. Hot dry summers and humid subtropical conditions do not suit it, so keep water up while it is young.
At maturity it reaches 20 to 25 metres tall with a 12 to 15 metre spread, so allow 8 to 12 metres of clear space around it. Parks, large gardens, school grounds, civic planting and wide avenues are its natural home. Deep summer shade and winter sun through bare branches is the practical trade.
Frequently Asked Questions
About Horse Chestnut
What is a Horse Chestnut tree?
Aesculus hippocastanum is a large deciduous shade tree from the Balkans, long planted in parks and avenues across the cooler parts of the world. It has a straight trunk, a broad rounded crown and big palmate leaves. Upright candles of white flowers marked yellow and pink appear in spring, followed by spiny seed cases.
How big does a Horse Chestnut grow?
It reaches 20 to 25 metres tall with a spread of 12 to 15 metres at maturity, which puts it firmly in the large tree category. Growth is moderate at 30 to 50 centimetres a year, so it takes decades to get there. Allow 8 to 12 metres of clear space around each tree.
Is it evergreen or deciduous?
Deciduous. The leaves colour yellow to brown and fall through autumn, leaving a bold branch structure over winter and letting sunlight into the space below. New growth breaks early in spring with the flower candles close behind. Expect a substantial autumn leaf drop, which is worth planning for above paths, gutters and pools.
When does it flower?
In spring, generally October and November in southern Australia, with timing shifting a few weeks by district. The flowers stand in upright panicles up to 20 centimetres tall, white with yellow and pink markings in the throat, and they are worked heavily by bees. Trees usually begin flowering at around ten years old.
Where does it grow best in Australia?
It needs a cool climate with a real winter, so Tasmania, southern Victoria, the Adelaide Hills, Canberra and the New South Wales tablelands are the districts where it does well. Deep, fertile, well drained soil gives the best results. Hot dry inland areas and humid subtropical coasts bring leaf scorch and poor growth.
Are horse chestnuts poisonous?
Yes. The glossy brown seeds, the leaves and the bark contain aesculin, which is toxic to people, dogs and horses if eaten. They are not the edible sweet chestnut sold for roasting. Children should be told the conkers are for play and not for eating, and fallen seed is worth raking up where dogs run.
How do I care for a Horse Chestnut?
Water deeply through the first few summers while the root system extends, and mulch a wide ring to keep the soil cool. It needs little pruning beyond removing crossing or damaged limbs in winter. Feed young trees in spring. Once established in a suitable climate it is long lived and largely undemanding.