Kelways Guide to Mahonias
Mahonias (or Oregon Grape) are impressive evergreen shrubs producing powerfully fragrant flowers, many during the winter, making for quite a statement piece and very easy to grow.
Best grown in full to partial shade and sheltered from cold winds, they will grow happily in pretty much any soil. Relatively slow growing, they require very little care other than the occasional prune to remove any dead wood. In colder weather, their leaves often take on red or purple hues.
A selection of some of the Mahonias available
A relatively new cultivar winning the Plant of the Year award at the 2013 RHS Chelsea Flower Show. A compact form growing to around 1m in height, it is the first cultivar to be introduced which has completely spineless leaves. An earlier flowering variety as well with fragrant, bright yellow flowers from late summer into autumn.
An evergreen shrub with large, glossy, evergreen holly-like foliage and producing slender spikes of fragrant yellow flowers throughout the winter, which are an invaluable source of nectar for pollinating insects during the colder months. These are followed by blue-black berries.
A larger growing variety which can ultimately attain up to 5m in height and a 4m spread, so be sure to give it plenty of space. A mature specimen can look stunning when covered in its yellow spikes in winter and will tolerate a sunny position so long as the soil remains moist.
A useful groundcover plant which spreads well owing to its suckering behaviour. It is particularly useful for inhibiting the growth of weeds in bare soil and a shady space. Typically growing to around 1m in height ultimately, it offers year round interest owing to it’s evergreen foliage and winter interest with its fragrant yellow flowers which are beneficial to pollinators during the winter months.
This cultivar of Mahonia aquifolium shares the characteristics of its parent, but with more dense clusters of yellow flowers. The spiny foliage is a useful deterrent and is sometimes grown as an informal low hedge in a shady spot. Growing to around 1m high and 1.5m spread.
To encourage bushy growth, every other year once the plants have finished flowering, prune them back to just above ground level. Mahnia aquifolium 'Apollo' has been awarded the RHS Award of Garden Merit.
An architectural plant with handsome, evergreen, holly-like foliage and slender spikes of fragrant yellow flowers in winter. One of the taller-growing varieties potentially reaching up to 5m in height, it is one to make sure you leave some room for it to develop. Underplant with shade-loving perennials and bulbs to conceal it’s lower stems. Mahonia x media 'Winter Sun' has been awarded the RHS Award of Garden Merit.
A hybrid between Mahonia and Berberis producing a mixture of simple, thin leaves and some more leathery leaves with lightly spiny edges. Clusters of fragrant yellow flowers appear in early summer sometimes followed by blue-black berries.