Heathers

Andromeda*: bog rosemary

One or perhaps 2 species distributed throughout the temperate parts of the northern hemisphere; the European and Asia plant is Andromeda polifolia*. North American plants are sometimes treated as a separate species, Andromeda glaucophylla, although the differences between the American plants and those from Eurasian populations are minor ones.

Calluna*

The single species, Calluna vulgaris, is very widely distributed throughout Western Europe including Azores, Iceland and Faeroe Islands, eastwards into Siberia, and southwards into northern Morocco in North Africa; this range represents about 125° longitude west to east and 36° latitude north to south. Calluna is reported reaching about 2,700m altitude in southern Switzerland. Calluna is also a naturalized exotic plant in many other places including North America(See Ref. 1 below), Australia and New Zealand. Ling, Calluna vulgaris, is native in Britain and Ireland. Low-growing, evergreen shrubs requiring acid soil. Calluna has minute leaves closely pressed to the shoots and small, usually lavender flowers in summer and early autumn. Suitable for USDA hardiness zone 5 but some cultivars are suitable for zone 4. This species is very variable, and the numerous selected cultivars (cultivated varieties) reflect, indeed exaggerate, this variation. In habit, ling ranges from prostrate, 5 x 45cm (2 x 18in), to erect and spreading 60 x 75cm (24 x 30in). The foliage varies in colour from dark green to bright green, grey, yellow, orange and red, and there are silver-foliaged plants too. The flowering time varies; in the northern part of the distribution it blooms from June to August, whilst in the southern part of the distribution it blooms from August to November. The white to crimson flowers normally possess a cup-like, four-lobed corolla about, 3mm (¹⁄₈in) long, overlapped by four sepals of similar size and colour. Double-flowered and bud-flowering (called 'bud-bloomers'(See Ref. 2 below)) variants also exist and generally bloom later. Ling is an important garden plant providing colour throughout the year. White-flowered ling – the original white heather – has long been associated with good luck and is a popular wedding flower.(See Ref. 3 below) Heather flower colours are usually defined by 16 colour groups called H1-H16. See the Heather Colour Chart for details of these colours. The H1-16 definitions for colours should not be confused with hardiness zones.

Daboecia*: St Dabeoc's heath

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. Low-growing or dwarf, evergreen shrubs that prefer acid soil. They have relatively large, elliptical, leathery leaves which are white or silver underneath, and the large, urn-shaped flowers, ranging in colour from white through lavender to deep purple, arranged erect spikes in summer. In gardens, St Dabeoc's heaths tend 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-colours. St Dabeoc's heaths tend to become straggly if not pruned annually. They can tolerate a little shade and are more resistant to drought than most heathers. Heather flower colours are usually defined by 16 colour groups called H1-H16. See the Heather Colour Chart for details of these colours. The H1-16 definitions for colours should not be confused with hardiness zones.

Cultivar lists can be found highlighted in blue throughout the text for each species.

Erica : non-European, including Cape heaths

The heaths called Cape heaths come from southern Africa, south of the Limpopo river, and mainly from the Western Cape Province of South Africa. In this relatively small area, about 700 species can be found. Erica is also represented in other parts of tropical Africa, especially on the higher mountains such as Mount Kenya and the Bale Mountains in Ethiopia(Ref: Heathers 2: 49-54 (2005)), and on some Indian Ocean islands including Madagascar(Ref: Heathers 8: 47-54 (2011)), Reunion and Mauritius(Ref: Heathers 11: 38-43(2014)). However these species are not in cultivation in the northern hemisphere. The weather pattern in southern Africa varies widely, affording specialized habitats for many species. In some areas, where Erica species grow, it is not uncommon to have heavy falls of snow, but frosts are rarely recorded. Most endure long, dry summers. Some of these non-European species are in cultivation but they are almost invariably not frost-hardy so must be kept indoors during winter in frost-prone areas. The species most common in cultivation, principally as specially selected cultivars, is Erica gracilis which is sold as a pot-plant during late autumn and winter for decoration at Halloween and All Saints-tide, and Christmas. Flowering months are indicated by Roman numerals (for example, VI (June), XII (December)).

Cultivar lists can be found highlighted in blue throughout the text for each species.

Erica Hardy

Northern hemisphere Erica species, hardy in most climates Heather flower colours are usually defined by 16 colour groups called H1-H16. See the Heather Colour Chart for details of these colours. The H1-16 definitions for colours should not be confused with hardiness zones.

Cultivar lists can be found highlighted in blue throughout the text for each species.