Oregon grape is good for a shaded corner
Published 03/05/2015 | 02:30
There is no shortage of yellow these days, with gorse blazing its mustard yellow on every roadside in a truly remarkable display and the great rush of yellow in gardens with forsythia, now just going out of flower. Adding to the splurge of cheery spring yellow is the Oregon grape, or mahonia.
The Oregon grape flowers that are open now will later develop into blue-black, grape-like berries, which give the plant part of its common name, and it is from Oregon and other parts of the north-western United States. The berries are not true grapes, just remarkably grape-like, including the blue waxy layer on the surface of the berries. The berries are not edible, being very tart and bitter, but they have been used to make jelly. Oregon grape is part of the berberis family. The family includes all the different kinds of berberis or barberry, including Darwin's barberry, which Charles Darwin collected in South America, and which also has been flowering in bright orange colour in gardens in recent weeks.
It is not difficult to see the family resemblance of Oregon grape with berberis. Both have clusters of small, bell-shaped flowers, usually yellow or reddish. Most have spines on the leaves, or stems, or both. The Oregon grape has leathery, evergreen leaves, divided into five or more holly-like leaflets.
The Oregon grape used to be more popular some years ago but, like a lot of good serviceable shrubs, it fell out of favour. It was used widely in commercial landscaping which tended to make it less appealing for garden use, but it is a good garden shrub. Its natural habitat is in woodland in partial shade and it is tough and long-lived.
The leathery leaves are present year-round and can provide some background winter greenery. Being dark green, the leaves are able to tolerate considerable shade and this facility makes the plant useful for shaded places that might not suit other plants. It can deal with dry soil too, being well able to compete with bigger shrubs and trees, once established.
The foliage may turn purple in winter and there is a selected form called 'Atropurpurea' that has good red-purple colour. 'Orange Flame' has orange-brown young foliage.
'Smaragd' is a more compact form with large flower clusters, but the plants available are mainly the basic species, unaltered from the wild plant. When suited, the shrub spreads slowly by suckers, but these are not a nuisance. The plant can be a bit straggly but the straggly bits can be cut down to allow new growth from lower down.