Growing Green: Fothergilla a shrub for four seasons
BY DIANE DORN
Special to The Press
Fothergilla, or witch alder, is a shrub native to the southeast United States that thrives in Pennsylvania gardens.
Fothergilla is a deciduous shrub that provides four seasons of interest.
In early April, white, one- to three-inch long, bottle brush-like blooms appear on the tips of its stems.
The flowers’ wonderful, honey-like fragrance is loved by early pollinators and sadly, deer.
The flowers fade after two to three weeks and are replaced by blue-green, leathery, oval leaves.
This shrub really shines as the weather turns cold.
The fall foliage color is stunning and differs because of weather conditions during the growing season.
The frost-tolerant leaves can be golden yellow, bright orange or red, depending on the amount of sunlight or rainfall.
Temperature may also affect the color display.
Fothergilla does develop non-descript fruit, a brown capsule containing two black seeds that forcibly eject upon ripening in summer.
In winter, the upright, fan-shaped stems provide an interesting appearance to your garden.
There are only two species of fothergilla, large fothergilla (Fothergilla major) and dwarf fothergilla (Fothergilla gardenii).
Both are native to the southeastern United States but grow well in Pennsylvania.
The flowers and leaves of each are nearly identical, but these two species have significant cultural differences to consider before adding to your home landscape.
Dwarf fothergillas naturally grow in damp areas along the coastal plain from North Carolina to Florida.
Their USDA hardiness zone is 5 through 9; the Lehigh Valley USDA hardiness zone is 7.
They prefer sun to light shade and moist, well-drained, acidic soil.
Depending on the cultivar, they grow anywhere from three- to six-feet-tall and two- to six-feet-wide.
Large fothergillas grow along ridges, riverbanks, and dry areas in the southern Appalachians, from North Carolina and Tennessee to Georgia and Alabama.
Their USDA hardiness zone is 4 through 8.
They prefer the sun to light shade and moist, well-drained, acidic soil.
They grow from four to 15 feet tall and six to 12 feet wide, depending on the cultivar.
There are several cultivars available in the retail trade.
The most commonly available is “Mt. Airy,” a naturally-occurring hybrid discovered by Dr. Michael Dirr at the Mount Airy Arboretum, Cincinnati, Ohio.
“Mt. Airy” has dark blue-green foliage, consistent yellow-orange-red autumn color, and abundant flowers with an upright habit of five to six feet tall.
Fothergillas are slow-growing shrubs with a mounded appearance.
With no serious insect or disease problems, they are long-lived.
Once blooms have faded, deer and rabbits leave them alone.
Use fothergillas as foundation plantings, in masses or along borders.
The brilliant autumn color makes them a good native alternative to burning bush or spirea.
They are difficult to propagate from seed, but soft wood cuttings root easily.
Fothergilla plants may spread by root suckering.
To control the spread, simply remove the suckers from the outer edges of the clump and prune to several central stems.
“Growing Green” is contributed by Lehigh County Extension Office Staff and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613








