Erica carnea or winter heath prefers cool summer temperatures so they may be better suited in containers that can be moved out of intense heat and sun of Eastern Shore summers. (Photo courtesy North Carolina State University)
During this month of St. Patrick’s Day, the plucky green Shamrock might be the first plant that springs to a gardener’s mind.
But devoted lovers of all things Emerald Isle related might also conjure a mental landscape carpeted with Irish heather.
If you’re imagining wide swaths of purple beckoning to you for a barefoot run, its possible your dreamscape has landed you in heather, which originated in Scotland instead of Ireland.
In Scotland, the genus Calluna vulgaris, commonly known as common heather or Ling, equals thistle as that nation’s symbolic image. It’s also considered invasive in its introduced areas of the United States, but other heaths in the same family, while non-native, can bring the year-round color and ground cover benefits as Ling.
Heaths and Heathers are both members of the Ericaceae family, but are further identified within the separate genus designations of Calluna and Erica, the main differential being winter hardiness.
A strain found growing wild in Ireland in the 1700s, designated as Daboecia, can also appear in purple, pink, magenta, and even white (Alba) varieties.
Daboecia (Daboecia cantabrica) is named for an early Irish Saint Dabeoc, also known as St. Beoc. It’s described by the Royal Horticultural Society, the United Kingdom’s leading gardening charity, as bushy dwarf evergreen shrubs categorized as a low maintenance, generally pest free ground cover suited to banks and slopes, which thrives in full sun and acidic soil.
The website for the former Heather Society, Heather World, offers a wider swath of discussion:
“There are two species of Daboecia. One is found only in the Azores and is sometimes treated as a subspecies of the more widespread St. Dabeoc’s heath, which inhabits western Ireland, and also ranges from south-western France through northern Spain into the north-west of Portugal. In cultivation these two species have accidentally hybridized, and the hybrid is now a popular garden plant.”
“They have relatively large, elliptical, leathery leaves which are white or silver underneath, and the large, urn-shaped flowers, ranging in color from white through lavender to deep purple, arranged erect spikes in summer,” the site continues. “In gardens, St. Dabeoc’s heath tends to have two flushes of flowers, the first in early summer and another in early autumn which continues until frost occurs.
“They are useful plants for ground-cover and for intermixing with other dwarf shrubs such as western gorse (Ulex gallii). They are particularly effective when planted in drifts of mixed flower color … and tend to become straggly if not pruned annually. They can tolerate a little shade and are more resistant to drought than most heathers.”
Mark Weathington, director of the J.C. Raulston Arboretum at North Carolina State University, recalled the variety Daboecia cantabrica “Atropurpurea” had been grown at the site’s xeric garden starting in 2009 with a natural lifespan of about a decade, featuring low mounds of evergreen foliage topped from early summer to fall with pinkish-purple bells.
It mixed happily with other plants requiring excellent drainage. Ultimately it grew to about 18 inches tall and 30 inches wide.
When pruned in spring as it comes into growth it would create a bushier, denser plant, Weathington said.
However, he pointed out that this type of heather is most suited to a Mediterranean type climate, and does especially well on the West Coast, especially coastal areas in Oregon.
The arboretum’s xeric garden was well amended to aid drainage and feature rock garden type characteristics.
One type of heath that grew extremely well there was the Erica darleyensis or ‘Darley Dale,’ reportedly first discovered at James Smith’s Nursery in Derbyshire, England about 1900.
It’s described by some garden centers as a hybrid between Erica carnea, also called winter heath, and Erica Erigena, Irish or Mediterranean heath.
Oregon State University characterized it as taller, more vigorous and with better frost hardiness overall, surviving in poor, even non-alkaline, growing conditions, but needing, like other heaths and heathers, good drainage.
For Mid-Shore gardeners wanting to try this Irish delight, containers with drainage-controlled soil might be the way to go.
Additional information about Irish heather, the book A Heritage of Beauty by botanist Charles Nelson includes two dozen cultivars of strictly Irish origin, one named in his honor.
At least two Facebook groups welcome those hoping to learn more, including The North American Heather Society and All About Heathers, whose administrator, David Edge, also suggested checking out the Irish Garden Plant Society (https://www.irishgardenplantsociety.com).
