RHS Garden Hyde Hall's Plant of the Month for November

Mahonias are an extremely useful and versatile plant...

The bright yellow MahoniaThey will happily grow in difficult situations where other plants will struggle, such as deep shade. Mahonia x media 'Lionel Fortescue' is evergreen and reaches around 3.5m (12ft) and can be used either as a single specimen to add structure to planting or as screening where its erect habit will act as a useful ‘filter’.

As the plant becomes taller its erect stems can become very bare at the base. To avoid this happening and to encourage the shrub to bush out, it should be pruned after it has finished flowering in the early spring. The flower head should be cut back to the next set of leaves from where it will re-shoot; although this will improve the shape of the shrub, the fruits will be lost for a year.

On extremely tall and old specimens that have long, bare stems, the stems can be cut hard back. Although there may be no leaves to prune to, a cut should be made just above a node from where it will re-shoot. Several specimens treated in this way at Hyde Hall last winter have now produced lots of new growth.
The leaves of the MahoniaMahonia has leathery, pinnate leaves which are dark green with 17–21 sharply toothed leaflets. As well as its adaptability, Mahonia is also grown for its late autumn and early winter flowers. ‘Lionel Fortescue’ bears bright yellow flowers in upright racemes up to 40cm (nearly 16in) long. If the shrub is un-pruned, blue fruits will develop through the spring. Mahonia prefers to be grown in humus-rich, moist, but well-drained soil in full or part shade but will tolerate sun if the soil remains moist. If it becomes dry they can become chlorotic.

At RHS Garden Hyde Hall we use mahonias through plantings to provide an evergreen back drop as well as in shady borders, and you can find this cultivar in the Queen Mother’s Garden in a mixed border. Around the base of the Mahonia, hostas provide textural interest which helps to hide the bare stems. You’ll also find this selection of Mahonia on Clover Hill where it is growing amongst other shrubs such as Euonymus europaeus, providing a backdrop to the perennial planting in this area as well as valuable late autumn and early winter colour.

Find out more here about chlorosis in leaves.

Read about soil types, and how to work with your soil.

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