GARDENING Growing edible chestnuts

The edible chestnut – a gourmet feast


Substainability
Andy Wilson

The last of the nuts to ripen is the edible chestnut (Castanea sativa). Uncommon in Mayo, edible chestnuts can sometimes be found on the old estates, where they were planted as a status symbol in colonial times. Last year I found a few decent-sized nuts underneath some chestnut trees growing just outside Westport. Since then I have been scouring the county for more good ‘nutters’ - my latest reported find’ has been a grand old tree on former estate land near Bohola.
Centuries of careful selection by chestnut growers have led to the development of hundreds of distinct named varieties of the chestnut. Some of these, particularly those originating in the west of France, are suitable for growing in Ireland. Viable nuts of a reasonable size found under mature trees growing near Westport in 2009 (after a very poor summer) confirm that chestnuts have the potential to do well in the west of Ireland.
The named varieties of chestnut, which are propagated through layering or grafting, produce much heavier, more viable crops, and will begin cropping at a much earlier age than trees raised from nuts. Although chestnuts raised from nuts will grow into fine trees, nut production is extremely uncertain.
Sweet chestnuts are normally not eaten raw but generally baked, boiled, roasted or used in confectionary. Chestnuts have also been used to make flour and for animal feed. The nuts normally ripen between late September and early November. Roasted or baked, they are delicious.

Growing your own
Chestnuts prefer a deep, well drained, loamy but slightly acid soil. They are intolerant of poor drainage, heavy clay and also dislike alkaline soils. In particular, waterlogged soil increases the risk of fungal or bacterial infections and other tree-health problems. Sunny but sheltered sites are best. The trees will eventually grow quite large so should be given plenty of room. Rotted bark or leaf mould added to the soil will prove beneficial.
Bare-rooted trees should be planted between November and the end of April, but not at times when the ground is either frozen or very wet. Spacing between trees should be 8-12 meters, with the narrower spacing for more exposed sites.
Cold or wet weather at flowering time (mid June to mid July) can lead to very poor pollination. However, the presence of plentiful bees and other insects will improve the outcome. For this reason, it is recommended that chestnuts are under-planted with flowering plants known to attract bees. Clovers and other ‘nitrogen-fixers’ are particularly recommended. Sheltered sites will also prove more attractive to bees. Where shelter does not exist, it can be created by planting shelter belts of alder.
The edible chestnut is sometimes confused with the unrelated but superficially similar Horse Chestnut - Aesculus hippocastanum. The Horse Chestnut is very common in Mayo. It produces the familiar conkers in September and early October. The nuts are not edible, though have been eaten in desperation in times of famine.

Sources
For more information on nut trees – or to get your own  – contact Fruit and Nut (www.fruitandnut.ie), based in Westport, carries the largest range of bare-rooted and container-grown nut trees in Connacht and also will undertake site assessments and/or provide free advice over the phone or by email. Phone 087 6714075 or email office@fruitandnut.ie.