Bartlett Tree Experts: Horse Chestnut

Aesculus Hippocastanum

The horse chestnut is widely regarded as a beautiful large tree (27m), so is ideal as a shade tree for large estates and gardens. The species is easily transplanted and grows rapidly while young. The white flowers occurring in panicles at the branch tips are the main ornamental feature of horse chestnut . Horse chestnut is weak wooded and develops leaf scorch during the summer. Sticky terminal winter buds and horseshoe leaf scars are distinctive features. The tree casts dense shade and has a coarse texture.

Culture
Concerns
Management

Culture for Horse Chestnut

Horse chestnut prefers full sun to partial shade, exposure sheltered from wind in moist, well drained soils. Ideal soil pH is 5.0-6.0.

Concerns about Horse Chestnut

Beset by many pests and diseases. Intensive management is required to ensure these trees remain healthy. The horse chestnut leaf miner causes total defoliation by late July, August. Pseudomonas bleeding canker can slowly kill trees over time. Scale insects damage leaves or branches by removing sap with their sucking mouthparts. Phytophthora root rot is another devastating disease of horse chestnut. Foliage diseases such as Guignardia leaf blotch can cause premature defoliation. Root and butt decay fungi include Armillaria, Ganoderma, and Ustilina.

Management Practices for Horse Chestnut

Spray trees with an appropriate insecticide in late April, mid May, and early June. Treat with phosphites for bleeding canker management. Apply as a soil drench and bark spray at the first signs of bleeding from the trunk. Air spading to alleviate soil compaction and control honey fungus or Phytophthora combined with soil applications of biochar, appropriate fertilisers, phosphites, and mulch.