The bottlebrush-shaped flower clusters appear in early spring just as the shrub begins to leaf out.
The cultivar 'Mount Airy' is an improved variety often planted in landscapes.
Dwarf fothergilla (Fothergilla gardenii) is quite similar to large fothergilla or witch-alder (F. major). Both fothergillas are small deciduous shrubs grown for their fragrant white bottlebrush-like flowers and colorful autumn foliage. The leaves are oval to obovate or nearly round, have toothed margins and are borne alternately along the stems. Those of dwarf fothergilla are around 2 in (5 cm) long, and those of large fothergilla around 3 or 4 in (7.5 or 10 cm) long. Leaves of both species turn bright red, orange or yellow in autumn. Flowers are without petals, but have long white stamens and are borne in terminal clusters 1-2 in (2.5–5 cm) long, the clusters looking like bottlebrushes. The flowers appear before or along with the first leaves in early spring. Dwarf fothergilla usually gets only about 3 ft (1 m) tall and wide, while the larger species can reach 8 ft (2.4 m) in height with a spread of 6 ft (2 m).
More than a dozen selections of fothergillas have been named. 'Blue Mist', a clone of dwarf fothergilla with glaucus bluish foliage, is often available and widely planted.
The two species of Fothergilla are largely allopatric: F. gardenii (dwarf fothergilla) occurs in wetlands on the Coastal Plain of the SE U.S. from North Carolina to the Florida Panhandle, and F. major (large fothergilla) occurs in woodlands on the Piedmont and in the Allegheny Mountains from Virginia and North Carolina to northern Alabama.
The fothergillas grow best in acidic soils that are well drained. They do not suffer limey soils. Light: Grow dwarf fothergilla in full sun to partial shade. Fothergilla will have more flowers and better autumn color in full sun. However, in the hottest parts of its range, dwarf fothergilla needs some protection from afternoon sun. Moisture: A humus-rich and leafy soil that usually stays moist but well drained is best for both fothergillas. Hardiness: USDA Zones 4-8. Dwarf fothergilla is known to have survived -25° F (-32°C). I have both fothergilla species here in my zone 8B woodland garden, but they do not seem to be thriving – just hanging on. They flower halfheartedly each spring, are growing slowly, and aren’t as colorful in autumn as they might be farther north. Global warming? Maybe my garden feels like the old zone 9A. Propagation: Plant seeds in autumn or winter for spring germination. Softwood cuttings taken in summer can be rooted under mist. The plant can also be air-layered.
This dwarf fothergilla planted in a perennial garden provides seasonal interest with early springtime flowers and late in the season with colorful autumn foliage. In summer it provides a handsome background for its colorful neighbors.
The fothergillas are best situated in a naturalistic woodland garden or a mixed shrub border. Place them where their autumn colors can be appreciated. In full sun fothergilla grows as a dense, bushy shrub that is remarkably attractive in bloom and again in its autumn plumage. Dwarf fothergilla goes well with native rhododendrons, mountain laurel, sweetshrub (Calycanthus floridus) and other southeastern American native shrubs. If you (like me) enjoy collecting obscure native shrubs, you should have a fothergilla!
Michael Dirr, the famous horticulturalist from the University of Georgia, says “without equivocation [the fothergillas] are among the most beautiful shrubs for autumn coloration.” Autumn leaves can be red, orange or yellow, often with different colored leaves on the same plant.
There are only two species of Fothergilla, both native to the southeastern United States. Other members of the family, Hamamelidaceae include sweetgum (Liquidambar styraciflua), witchhazel (Hamamelis virginiana) and loropetalum (Loropetalum chinense), as well as several species in China, Africa and even Australia.