Lemon verbena is a popular shrub that was introduced into Western horticulture from Chile and Argentina as long ago as 1794. It is still cultivated extensively as a garden shrub and as a medicinal and culinary herb. Botanical names that have been accorded to the plant include Aloysia citriodora and Lippia citriodora, but ALOYSIA triphylla is the preferred name at present.
ALOYSIA triphylla is quick growing and has strongly aromatic, lemon-scented foliage – it is grown largely for these aromatic properties. It has a rather scraggly growth habit and can grow to 3 metres tall and equally as wide if left to grow unchecked. The leaves are slender and grow to 10 cm long; they are borne in whorls of three or four along the lengths of the stems. Flowers are produced in terminal panicles from late spring through into summer. The tiny flowers are white, lavender or lilac, and are not particularly attractive.
Lemon verbena is deciduous and during winter the plants go into complete dormancy. The new spring growth emerges when temperatures and day length increase in spring. In extremely cold climates new growth can be delayed by spring cold and it then only bursts forth in early summer.
This useful garden shrub is easy to grow, preferring full sun and well drained soil conditions. Regular pinching and pruning of new growth tips will help to keep shrubs compact and bushy through the growing season. Old, woody plants can be pruned back hard in spring to encourage healthy new growth from the base. Regular applications of a balanced garden fertiliser from spring to autumn will help maintain lush foliage. Grow lemon verbena in shrubberies and herb gardens, and in pots and containers on patios and other high profile areas where the aromatic foliage can be touched and harvested regularly. Sprigs of foliage are effective as a natural air freshener, so keep them in vases indoors to enhance the air quality. The foliage is used extensively in potpourris, and lemon verbena oil was popular in perfumery. The leaves are also used in herbal teas, poultry stuffing and salads, and to flavour jellies and summer drinks.
Lemon verbena is a most useful and versatile shrub that grows easily in most parts of South Africa. It is well worth having in every garden, even if only to touch and stroke whilst wandering about at home after a hard day at work – the rich and distinctive aroma of the leaves is so soothing and relaxing.