Fothergilla x intermedia Mount Airy - Witch Alder

Fothergilla x intermedia 'Mount Airy' is a hybrid variety of Fothergilla major awarded with a Royal Horticultural Society Award of Garden Merit for its qualities. It offers a spring flowering with white bottlebrushes and a honey fragrance on its still bare branches, before developing a leathery blue-green foliage. Flamboyant in autumn, its leaves turn yellow, orange, and purple-red. Highly disease-resistant, it forms a rather small bush, suitable for gardens of all sizes, and is interesting in more ways than one. It appreciates moist and well-drained soil in full sun or partial shade, but can also tolerate slightly dry conditions. It does not tolerate limestone.

Native to North America, Fothergilla is a shrub classified in the Hamamelidaceae family. There are only two species of fothergilla, the large fothergilla, Fothergilla major, and the dwarf fothergilla, F. gardenii. The two species are almost identical, except for the size of the flowers and leaves, and the overall dimensions of the shrubs. The plant has an upright habit and slow growth. Fothergilla major rarely exceeds 2 m in height and 1.50 m in width. It grows in the mountains of South and North Carolina, in fairly dry, acidic soils, in partial shade.

Fothergilla has a bushy, compact, yet flexible habit. Its growth is slow. Its deciduous foliage somewhat resembles that of the hazelnut tree. It consists of diamond-shaped, hairy, embossed leaves with prominent veins, initially light green, then darkening in summer. They turn colourful in autumn, filling the garden with sumptuous hues. Its flowers, in conical bottlebrushes measuring 3.5 cm in length, are white and fragrant, as delightful as its colourful foliage. They abundantly cover the grey, bare branches during April-May. Each inflorescence is composed of flowers, with numerous recurved stamens, embedded in a green to cream-coloured calyx. The colour varies from white to cream, with the tip of the 'bottlebrush' being chartreuse green.

Fothergilla intermedia 'Mount Airy' reaches a height of 1 m to 1.30 m at maturity, with an equivalent width. It is a very popular selection in the United States, reliable, robust, and healthy.

This cultivar 'Mount Airy' thrives in full sun or partial shade. It prefers acidic, damp, and light soils, but can tolerate slightly drier conditions. Its autumn colouration is more intense when grown in full sun. Plant it on the edge of a woodland, in a bed of acid soil plants, alongside Daphnes, Pieris, and Sarcococca or Autumn Camellias. Plant Heucheras with a colour similar to its beautiful autumn colouration at its base, which will create a beautiful echo. Winter heathers or hellebores are also good companions.