Fruit is far more common in late summer and autumn, when warm settled weather ripens them.
Mahonia oiwakensis, synonym M. lomariifolia, does the opposite to the norm, producing yellow flower spikes in autumn and then ripening its fruit in spring. Beautiful displays of bunches of blue grape-like fruit contrast well against the glossy green foliage.
A great shrub from China with a variety of uses in the garden, Mahonia oiwakensis is a narrow evergreen growing to 3m-4m tall. This makes it particularly useful for the back of a border, in a mixed shrub border or as an informal hedge.
One should be aware of its rather prickly foliage; position it away from where people might brush up against it. On the other hand, this feature is very useful for using as a barrier to stop people going into unwanted areas.
Pruning is easy and the shrub will shoot away if pruned hard. Fortunately, it doesn’t seem to have any pest or disease issues. Mahonia oiwakensis likes to have some light shade, moist soil and good drainage. It will survive reasonably hard frosts but dislikes strong winds when young.
Propagation is by seed or semi-hardwood tip cuttings in summer.
You can see it in a number of different locations around the Dunedin Botanic Garden, including a display behind the bandstand in the lower garden.
- Garden Life is produced by the Dunedin Botanic Garden. For further information contact Stephen Bishop.
