Updated: Mar 23, 2020
The Wych Elm or Scots Elm is a deciduous tree that can grow up to 30 meters and is a Native of South and Central Europe and Western Asia. While they were once the most prolific of Elm, they are now considered an endangered species as their numbers have been severely reduced by the Dutch Elm Disease.
Styles & Sizes: As bonsai, they make Medium to Large sized Bonsai in most upright forms. It is an excellent way of preserving this species because the small sizes of bonsai do not attract the beetle that attacks the Elms and carries the fungus that causes the Dutch Elm disease.
Position: The prefer a full-sun area, though at the height of summer some bonsai may prefer a dappled shade location. While they are hardy bonsai plants if winter temperatures fall below -4C then they are best over-wintered in an unheated greenhouse.
Feeding: Feed with a balanced organic feed, every two weeks if using a liquid feed, every other month if using a pelletised version or after the pellets have fully dissolved away. Feed the bonsai between early spring and the end of summer.
Repotting: Young Elm’s grow roots rapidly and need to be repotted every year. Older trees can be re-potted as necessary, generally, if the growth in the current year is not as healthy as it can be it will benefit from a repotting in the following spring. Use a well-mulched bark, sharp sand, in equal parts. Alternatively, you can use a mix of Akadama, Pumice in the ration of two to one.
Pruning: Trim back shoots to leave 3 leaves on stem once the stem has fully extended. It is wise to make substantial pruning cuts late in the season, to avoid excessive sap ‘bleed.’
Wiring: The ‘clip and grow’ method is best for styling. If wiring is required, wire in autumn, and remove before spring sets in entirely.