Helen McKerral takes a look at a plant group that’s a collector’s dream.

Most gardeners and cooks know and love the delicious herb sage (Salvia officinalis), cosy partner of parsley, rosemary and thyme, perfect in stuffings and sauces, stews and soups. But common garden sage is but one member of a genus of at least 900 species of annuals and herbaceous and shrubby perennials, many of which have equal claims to fame. Not only that, but with such a huge number of different salvias, this group has become a plant collector’s paradise (see Web Watch below). Best of all, no salvia enthusiast will ever run out of plants to collect because new cultivars appear on the market every year!

The salvia genus is in the mint family (Lamiaceae), so the leaves of many are strongly aromatic. Pineapple sage (S. elegans) and fruity sage (S. dorisiana) are delicious in drinks, but not all salvias are attractively scented: clary sage (S. sclarea) has been used to flavour wines and as a potent substitute for hops, but this is rather surprising because its other common name, ‘Hot Housemaid’ describes its pungency all too well!

Nevertheless, even the more, well, fetid members of this family make worthy garden plants. They may boast beautiful foliage (S. argentea has huge, furred silvery leaves) or provide a spectacular flower display. Blooms come in almost every shade imaginable, including unusual ones like the "true" blue S. patens, the brown S. africana-lutea, the purple-black S. ‘Black Knight’ and 'Purple Majesty' and the hot pink, cerise and salmon tones of S. greggii cultivars. The papery bracts that cup the petals are often equally brightly coloured, sometimes in a contrasting hue, and they remain long after the flowers fade. Different species of salvia bloom in different seasons, with some blooming for two or three seasons, so with just a handful of varieties you can have colour in your garden every month of the year.

Growing salvias

Salvias are distributed throughout the world, and are therefore adapted to a wide range of growing conditions. Nevertheless, some general guidelines apply. Depending on their habit and origin, salvias may be frost tender or hardy. Generally, shrubby varieties - those with woody stems and soft leaves - and annuals are more frost sensitive, while herbaceous perennials - those that are deciduous over winter, dying back to a crown at or just below ground level - are hardier.

Most salvias prefer a temperate climate but some are tolerant of more humid conditions, so be guided by what’s available in your local nursery. Nearly all do best in full sun, though some will flower in dappled or semi shade and others need protection from hot, dry winds. You can usually recognise the ones that need more shelter by their large, soft and/or fleshy leaves (eg. S. dorisiana, S. guaranitica) that are more prone to wilting, than species with small, leathery leaves (S. africana lutea, for example, is extremely drought-tolerant).

Almost without exception, salvias need well drained soil (one exception is bog sage, or S. ulignosa). Raised beds and rockeries are ideal; heavy soils should be improved with compost or gypsum. Salvias are not gross feeders and a mulch of compost in spring or a light dressing of complete fertiliser is plenty for most. Too much fertiliser creates lush, leafy plants without flowers.

Pruning

With garden salvias, pruning is the key to maintaining their vigour and promoting an attractive, compact habit. Unless you’re collecting seed, remove spent flower spikes from herbaceous varieties to stimulate a second and even third flush of blooms.

When pruning woody-stemmed varieties, there is just one thing to remember: cut plants back very hard, but never prune to bare wood. Many growers recommend that you wait until you see new shoots emerging from near the base of the plant before you cut. Hold back even longer in frost prone areas - the old stems will protect the fresh growth. Pruning is generally done after flowering, but this can be difficult when some varieties flower almost continuously! In this case, watch for that new growth, and prune then.

Salvias to try:

Annuals (or grown as annuals in colder climates):

S. splendens : Brilliant fire-engine red blooms. Excellent bedding variety, available in punnets or grown from seed. 50 cm

S. farinacea: Another excellent fast-growing bedding variety, whose blue or white blooms are shown to best advantage in mass plantings. 50 cm.

S. columbariae: Small flowers but large, brightly coloured, long-lasting bracts. Dead-head regularly to extend the display. 30 cm.

Scented/Culinary

S.officinalis (common sage) cultivars: As well as the common green-leaved variety, look for S. o. ‘Purpurascens’ (purple foliage), S. o. ‘Tricolor’ (Variegated in purple, cream and green), and S.o. ‘Icterina’ (green and gold). White and pink flowered forms are also available from specialist nurseries. Give common sage full sun for best flavour.

S. dorisiana (fruity sage): A shrubby, soft leaved species (will grow in semi shade) whose leaves have a fruity scent. Deep pink flowers. 1.8m.

S. elegans (pineapple sage): A shrubby species whose bright red flowers appear in summer and autumn, and into winter in mild climates. Use leaves and flowers in desserts, salads and punches. 1.8m.

S. sclarea (clary sage): Biennial or short-lived perennial with large aromatic leaves. Tall spikes of mauve- white flowers reach 1m.

Drought tolerant

S. africana-lutea (brown salvia): A hardy, shrubby species with large brown flowers. 1.8m. Prune to keep compact.

Beautiful flowers

S. patens: Tuberous herbaceous & deciduous perennial with bright blue flowers. 50 cm.

S. guaranitica: Spreading perennial for sunny sheltered spot or semi-shade, with deep blue flowers (cultivars in other colours are available). Deciduous in cool regions. 1.8m.

S. uliginosa (bog sage): herbaceous perennial spreading on underground runners, and with tall spikes of pale blue flowers in summer. Tolerant of heavy soils and wettish conditions. Deciduous. 1.5m

S. azurea: Similar to bog sage but flowering later, and with darker, azure-blue blooms. 1.5 m.

S. greggii: Small woody shrub with masses of blooms from spring to autumn. Many named cultivars and hybrids with flowers in many bold and unusual colours (red, salmon, apricot, yellow). 1m

S. involucrata ‘Bethellii’: Beautiful red-pink blooms atop lush foliage that’s evergreen in mild climates. 1.5m.

S. leucantha: Spreading species with woolly mauve and white flowers carried for months on end, and lovely grey foliage. 1 m.

S. forsskaolii: Clumping perennial with mauve, pink or white flowers borne on tall spikes for at least 9 months of the year (in my garden, anyway!). 70 cm.

You’ll find numerous other species and cultivars in garden centres, or try mail order and specialist nurseries for the more unusual salvias.

Web Watch:

Tip: Type "salvias" into your search engine for a comprehensive listing.

groups.yahoo.com/group/Salvia/

www.cabrillo.cc.ca.us/divisions/becho/hort/salvias/html/

Illustrations from top to bottom:
Salvia 'Purple Majesty'
S. patens
S. leucantha