The native heather, Calluna vulgaris, is a common sight in upland areas where it benefits a range of wildlife, particularly pollinating insects. It has been equally beneficial to plant breeders, giving rise to myriad cultivars, which provide a huge range of foliage colours and a flowering season from June to November.
For landscapers, a heather bed justifies itself by being fully hardy, long-lived, low-maintenance and by offering year-round interest.
Calluna is at its best planted in like company. Groupings with similarly textured conifers are popular as well. It can also be planted to almost any scale, from planters and small island beds to larger expanses where it is almost an alternative to open grass.
Foliage colour is often the main attribute of Calluna's many varieties. As well as single colours such as gold, bright green, terracotta, grey and purple-brown, there are bi-tone and tip-colour variations. Beyond this, many develop additional tints during the winter.
The main flowering months are July and August, although a few varieties will start in June and others will end in November. The palette runs from purple and pink through to white. Many varieties are double-flowered, although for pollinating insects, singles are best. In so-called "bud bloomers", the flowers remain closed, extending the flowering season into November.
Calluna is particular about soil requirements, needing a well-drained yet moisture-retentive, open, sunny site. Where heavy clay is present, a raised bed may be the only option. The most important element is pH and this should be acidic. For light soils, where this is not the case, conditioners can be added to lower the value. Aside from peat, sulphur chips are a good choice for longer-term soil acidification.
Once planted, Calluna will need care in its first year to aid establishment, mainly to prevent it from drying out. A weed-suppressing fabric or mulch is also recommended. Thereafter, as its fine fibrous root system spreads and dense carpet of foliage develops, it will become largely self-sufficient.
Propagation is predominantly by cuttings in summer or layering. Whole bushes can even be dug up in autumn and re-planted deeper than before, where it can be expected to re-root along the buried branches, regenerating old plants or providing new rooted material. Seed is also an option, but can often be erratic and is not an option for named varieties.
Calluna is largely untroubled by pests, although it may attract aphids in late spring. Damage by fungal diseases such as Botrytis may be more problematic, particularly in warm, wet weather, in which case affected growth is best removed. Fallen leaves and other debris should also be cleared.
WHAT THE SPECIALISTS SAY
Noel Allan, partner, Galloway Heather, Dumfries & Galloway "Calluna vulgaris is excellent for ground cover and for year-round colour. We do stock quite a few varieties - people come to us from all over the UK and the EU to get the ones not usually found in garden centres.
"Good varieties are C. vulgaris 'Annemarie' Award of Garden Merit (AGM), 'County Wicklow' AGM and doubles like 'Kinlochruel'. Doubles are ideal for flower arrangements as they last longer. For foliage, something like C. vulgaris 'Silver Knight' looks good in smaller collections. Then there are tip-tones like 'Spring Cream' and 'Spring Touch'. Size varies; some are only 5-7cm high while others, such as C. vulgaris 'Silver Knight', grow up to 45cm. All must be pruned after flowering or else they get straggly."
John Hall, proprietor, John Hall Plants, Hampshire, and chairman, British Heather Growers Association "We supply a lot of C. vulgaris for reclamation projects, such as an old quarry where we supplied thousands, and to golf courses, aiding their Site of Special Scientific Interest status. I'm trying to encourage landscapers and designers to use natural C. vulgaris in their schemes for its wildlife value. But 90 per cent of our stock goes to garden centres and thus are commercial varieties.
"Our best-selling Calluna is C. vulgaris 'Dark Beauty' AGM. It's very compact and a good performer. I grow 50 varieties, with new ones added like C. vulgaris 'Stephanie', a clear white flower on bright green foliage.
"Straggling is easy to get over if heathers are trimmed below the flower spikes for the first few years after flowering. This encourages new breaks from the base and thereafter they are fine."
Julian Fitz-Earle, manager, Springpark Nursery, Kent "Heathers are usually sourced in 5-7cm pots, but we supply a lot in five- to 10-litre pots to create an instant effect. We find they are used quite considerably on golf courses and bowling greens. Calluna and grass work well together. We have also supplied to a number of themed castle gardens. For a 'golden glade' theme we used C. vulgaris 'Golden Carpet', 'Gold House' and 'Darts Gold'.
"Many varieties have different coloured tips, going red, gold or white. There's a great demand from landscapers to use them at the moment."
Ed Ikin, head gardener, Nymans Garden House, West Sussex "We are revitalising our heather beds at the moment and have a collection of Calluna varieties that have been bred at one time or other in Sussex. We sourced these from a local nursery and these are the ones which are doing best for us.
"We've got 'Ditchling Beacon' and 'Edith Godbolt' - all the Sussex-related heathers. Success seems to vary from cultivar to cultivar - some are prone to sun scorch, and fungus disease also takes a toll. The first few years are the most tricky. But we are lucky as our grounds suit them."
SPECIES AND CULTIVARS
- C. vulgaris is a low-growing evergreen shrub with dark green foliage, often purple-tipped. The pink-purple flowers appear from late July through to September. Growth is usually tangled, forming a spreading open bush.Its height is 60cm with a 90cm spread.
- C. vulgaris 'Alexandra' Award of Garden Merit (AGM) starts bi-coloured in white/crimson and later darkens to a richer red. It flowers from August to December and grows to 30cm and spreads to 40cm.
- C. vulgaris 'Annemarie' AGM is a double with deep pink flowers appearing September to October. Growth is reasonably dense with dark green foliage. Its height and spread reach up to 60cm.
- C. vulgaris 'Beoley Gold' AGM carries white flowers from August to September and yellow foliage through the year. It is upright with a well-shaped golden dome. It grows up to 45cm.
- C. vulgaris 'County Wicklow' AGM is a variety of Irish origin and has large, double flowers in a fine shade of pink during August to October. Foliage is a mid-green and the plant grows to 20-25cm with a spread of 30-45cm.
- C. vulgaris 'Dark Beauty' AGM has semi-double flowers in a red-purple during August to October. A relatively recent variety, it has a compact growth habit and reaches up to 25cm, with a spread up to 45cm.
- C. vulgaris 'Firefly' AGM combines its mauve flowers in August and September with striking foliage in terracotta. This later darkens to warm brick red in winter. It has an upright growth habit and can reach 45cm.
- C. vulgaris 'Flamingo' starts the year in spring with new growth in pink. Its lavender flowers in August and September combine with dark green foliage. It forms a bush up to 25-30cm high with a spread of 45-60cm.
- C. vulgaris 'Gold Haze' AGM has green-yellow foliage with single, white flowers during August to October. It is a neat grower with an upright habit, forming a low mound. It reaches 25-30cm with a spread of 30-45cm.
- C. vulgaris 'Golden Carpet' has a prostrate habit with slightly contorted growth. The yellow-green foliage turns to orange in winter. The flowers, in mauve, appear in September and October. It grows to 10-15cm.
- C. vulgaris 'Kinlochruel' AGM bears pure white, double flowers in August to September. Its bright green foliage takes on bronze tints during winter. It reaches up to 25cm in height with a spread of 45cm.
- C. vulgaris 'Peter Sparkes' AGM displays well with long lengths of double pink flowers and dark green foliage. It has a long flowering season from August to November. Its height is 25-30cm with a spread of 45-60cm.
- C. vulgaris 'Radnor' AGM is a Welsh variety, bearing double flowers in a clear pink from July to October. Growth is compact and the foliage is a bright green. It can reach up to 25cm and spreads 30-40cm.
- C. vulgaris 'Silver Knight' is a well-known variety with velvety, grey foliage. This contasts well with the lavender flowers during August and September. Foliage colour intensifies in winter, becoming purple. It is a strong grower and reaches 40cm.
- C. vulgaris 'Velvet Fascination' AGM is similar to 'Silver Knight', from which it is derived, but with a more open habit. Strongly upright in growth, its colours well in winter. The white flowers are borne in abundance during late summer. It can reach a height of 60cm and with a spread of 75cm.
- C. vulgaris 'Wickwar Flame' AGM has good foliage-colour combinations, mainly golden, but taking on shades of orange and red during the winter. The pale purple flowers from late summer up to November form a good contrast. It reaches a height of 60cm.
- C. vulgaris 'Winter Chocolate' features an interesting purple-brown coloured foliage, which distinguishes this taller-growing variety. Young growth in spring forms a good contrast in light green, turning later to dark pink. Its lavender flowers show from August to September. The plant can reach up to 20cm, with a spread of 40cm.
- C. vulgaris 'Silver Knight' is a well-known variety with velvety grey foliage. This contasts well with the lavender flowers during August and September. Foliage colour intensifies in winter, becoming purple. It is a strong grower and reaches 40cm.