Mahonia tend to get a bad press because they are often seen in landscaping arrangements around supermarkets and roundabouts. Seems harsh as Mahonia are an easy to grow shrub which look good in many settings and give late winter colour, with scented flowers and berries for the wildlife. On mass their bright yellow flowers are attractive and some varieties, see below, have scented flowers.
Mahonia are mostly a trouble free shrubs which makes them fairly easy to grow. They look good in a border mixed in with other evergreen shrubs and are fast growing. Mahonia can be planted on the perimeter and will make a good security hedge which because of their very spiky thorns. (image right)
Mahonia are evergreen with deep green glossy foliage which is attractive commonly in flower late autumn from December on wards with yellow flowers some of which are fragrant. Mahonia are best situated in part sun/part shade but are shade tolerant. The winter flowers provide late winter /early spring nectar for any solitary bees emerging from hibernation. Mahonia are an attractive shrub, the evergreen foliage is glossy and looks a bit like that on hollies, and the bright yellow flowers have lovely fragrance and last for many weeks.
Which Mahonia to grow?
The most commonly grown Mahonia are upright and tall but in fact there are many varieties with of different sizes although all tend to be fast growing. The group of Mahonia known as M. x media are all upright varieties, and illustrated below left is 'Charity' which has lovely yellow fragrant flowers. The upright varieties are the most common, but there are also a low growing varieties, Mahonia repens, which grows up to 30cms, illustrated in the image below right and can be used as ground cover.
The most popular varieties grown in UK gardens are:
Mahonia x media which grows up to 5m high 4 m wide and flowers from late autumn to early winter; good varieties are 'Charity', 'Winter sun' and 'Lionel Fortescue' and all are very hardy H4. These have large upright yellow, scented flowers. 'Charity' can be grown in a north facing spot which makes it a good shrub for a difficult growing area.
Mahonia fortunei smaller 1.2m high 1 m wide which flowers in the autumn
Mahonia aquifolium known as the Oregon Grape, image left is a smaller compact variety, up to 1.5 metres, very hardy and is spring flowering in March and April followed by blue black berries.
A recent introduction is a red flowering Mahonia called Mahonia nitens 'Cabaret' which flowers in late summer and autumn.
When growing Mahonia you do not have to prune the shrub, but a light prune, from time to time after flowering, will trim the shrub into shape and remove any dead branches.
Mahonia look good under planted with snow drops and Hellebores to provide a mixed winter border. Suitable companion shrubs would be Berberis if making a thorny hedge, or Rhododendron, Azalea and Viburnum if planting a mixed shrub border.
Planting a Mahonia is easy; soak the root ball in water for 20mins and dig a hole about twice the size of the plant. Place in centre so that the top of the plant in the pot is level with the soil; back fill with good peat free compost firm in and water again.
Problems growing Mahonia
Sometimes mature Mahonia can get leggy and bare at the base with all the leaves and flowers in the top growth. Mahonia can be left unpruned, but if the shrub has become leggy and bare, prune out the leggy branches after flowering, or hard prune the whole shrub. Some gardening advise suggests to prune out one third of the branches annually to prevent the shrub becoming bare.