There are many different varieties of Mahonia but the one most of us are referring to is mahonia aquifolium. This has holly-like leaves and grows to about four feet in height with 
a similar spread. This plant is sometimes known as the Oregon Grape because of the clusters of dark blue berries that it carries in autumn.
It is a useful evergreen shrub in British and Irish gardens because it is totally hardy and grows absolutely anywhere.
Use it in a mixed hedge to give some winter privacy or use it within the confines of your own garden to divide off particular areas. I screen my compost heaps with a few mahonia aquifolium shrubs.
You can buy mahonia as tiny bare-root shrubs from Lidl™ and Aldi™ in spring and autumn for only a few pounds or euro each and these will grow quickly to a respectable size. I prefer to buy my shrubs in March because I have lost too many October-bought shrubs to frost and I live in Cork, one of the mildest parts of Ireland.
Pruning mahonias is not necessary; that is one of the major plus points about mahonia (Oregon Grape), it never needs pruning. If you want a medium height zero-maintenance height then this is the shrub for you.
Mahonia shrubs are perfect for small gardens because they only grow to four feet high and they have multiple attractive features. They flower through spring and summer, have berries through autumn and early winter, attract birds and bees and they are evergreen so keep weeds down around their bases.
The only feature you might find unattractive is their holly-like leaves, which are uncomfortable if a child brushes against them.
