This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Amongst dwarf evergreen shrubs Heaths occupy an important position. They flourish in a peaty soil, or in one composed chiefly of leaf mould, and will also do well in a mixture of peat and loam. Thousands of plants are grown in some nurseries, indicating a good volume of trade. With the exception of such kinds as arborea, ciliaris, cinerea, codonodes, mediterranea, and vulgaris, which attain a height of 2 to 10 ft., the average height is between 6 and 18 in. They form bold masses of greenery, and when in bloom they are decidedly attractive. Propagation is by seeds, cuttings, and layers. Amongst the best-selling kinds are arborea, white, rather tender; carnea (herbacea), white, pink, and purple varieties, in flower from January to April; ciliaris, the Dorset Heath, pale red, from June to September; cinerea, crimson purple, July to September. There are white-flowered varieties with larger and smaller flowers than the type. Codonodes (lusitanica), the Spanish Heath, grows up to 10 ft. high in the south, flowers white or tinted rose, from January to May; mediterranea, white and pink, April and May; the variety hibernica (Irish Heath) grows 5 ft. high. Hybrida, said to be a cross between mediterranea and carnea, produces its bright pink-purple flowers profusely from Christmas to March and April. Tetralix, the Cross-leaved Heath, has downy leaves and terminal clusters of rose-red flowers from July to September. There are several varieties, including a deep-red one, rubrum. The Cornish Heath, E. vagans, has pink flowers, with conspicuous protruding anthers. There are several varieties - alba, grandiflora, leucantha, rubra, etc. July to September. The Common Ling, E. vulgaris (Calluna), has many varieties, some with double flowers and some with variegated and golden foliage, the best-known being alba (the "White Heather"), Alporti, aurea, erecta, Ham-mondi, minor, pilosa rigida, Serlei, tenella, tomentosa, etc. July to September. The Greenhouse Heaths are dealt with in Vol. II, p. 173.