The Wonderful World of Salvias by Janet Buist

Salvia involucrata ‘Boutin’ Mexico

The speaker at our well-attended meeting on 18th April was Janet Buist on the subject of The Wonderful World of Salvias. Janet was until her recent retirement the owner of Pennycross Nursery which specialised in salvias. There are over a thousand different species of salvia and the number is growing rapidly with new introductions. Janet said she is often asked how to look after them and there are no easy answers as their requirements vary a great deal. Salvias come from all parts of the word except Australasia although chiefly from the New World and these varieties were the main subject of her talk …
The name salvia comes from the Latin ‘salus‘ or ‘salve’ which means safe or unharmed and, hence, good health and many salvias do have a medicinal use. The common name for salvia is sage and many sages are used as herbs. Janet instanced salvia ‘officinalis’, the common sage, ’hispanica’ for chia seeds and ‘divinorum’ which is a hallucinogenic drug.
Janet continued her talk with information about the people mainly responsible for the marked growth in salvias’ popularity. Pat Vlastor and Chriistine Yeo were associated with the growth of the Plant Heritage movement which has established national collections of plants to ensure their conservation and development and they both set up collections of salvias. James Crompton went plant hunting in Mexico and introduced many new species from that area. Robert Middleton promotes information on his website and William Dyson is a breeder running Great Comp a specialist nursey near Sevenoaks. The popularity of salvias is due to their huge range of colours, enhanced by calyces with contrasting colour, and their long flowering period; often from May to December. With a conservatory or heated greenhouse it is possible to have them flowering at any time of the year.
Janet gave a brief survey of salvias coming from areas other than the New World which included a few native to this country. She then gave wide coverage to the New World species and, particularly Mexico. All the species Janet mentioned, and there were over thirty in all plus named varieties, were amply illustrated with excellent and informative photographs. Salvias cover a wide range of plants including annual bedding, biennials, hardy and tender perennials and shrubs and they can range in height from ground cover to six feet.
Janet then spoke about the practical aspects of growing salvias starting with cultivation. Most need well drained soil in full sun. William Dyson divides salvias into four groups for cultivation. Firstly, shrubs which are often evergreen although they may lose their foliage in a hard winter. They don’t tolerate wet conditions and in a hard winter it is advisable to cover them with a cloche to keep the roots dry. They should be pruned in spring to half their height and they may benefit from the ‘Hampton Hack’ – cutting them back in July which delays flowering but increases its density. Hardy herbaceous perennials may be cut down by frost but will regrow, although rather late. Tender evergreens need frost free cover under glass in a heated greenhouse or conservatory.
Propagation can be either by taking seeds or from cuttings. Annuals and biennials should be propagated by taking seeds. The seeds should be stored in a fridge and sown in February in a heated propagator. Germination takes two to three weeks. Cuttings can be taken from the tips of herbaceous perennials and shrubs at any time after growth is sufficient until August. Ideally take shoots without flowers but otherwise remove the flowers. Use clean tools and put cuttings immediately in a plastic bag. Remove the lower few leaves and reduce leaf size for large leaved varieties. Use two thirds multi-purpose compost and one third Perlite mixed and put eight or nine cuttings in a five inch pot. Water and cover with a plastic bag held upright by four small canes. Grow in a warm but shady place. Turn the plastic bag inside out every couple of days to stop humidity building up and water occasionally.
Salvias are not greatly troubled by pests and diseases but they are not trouble free. Slugs and snails can be a threat and need treating accordingly. Whitefly can occur in a greenhouse and capsid bugs can cause holes in the foliage. Spray with a systemic insecticide if available. Powdery mildew should be treated with a fungicide.. Under glass keep humidity as low as possible to avoid botrytis and ventilate when possible.
Janet’s talk was an exhaustive and very informative survey of the wonderful world of salvias which was much appreciated by the audience.
Jeremy Arthern.

A selection of photos shown during Janet’s presentation:

view more photos of Salvias (flickr)

Our next meeting will be on 16th May when Steve Brooks will give a talk on ‘Greatest Gardening Tips’.