Lots of flowers in the garden are firmly in decline by the middle of September, just when a lot of salvias are just getting going. Most come from South America and they are prompted to flower by evenly balanced days which give them 12 hours of daylight, conditions they normally get in their native land. Their lateness puts gardeners off and the fact that many have to be moved indoors, due to lack of hardiness, doesn’t help either. Yet few plants offer such wonderful foliage and such exotic-looking flowers so late into the year. Salvia involucrata ‘Boutin’ (pictured right) is a large woody salvia with fascinating shrimp-like buds that open to produce red-pink flowers. It will flower until November and is hardy to -11C so many in the south of England leave this plant in. This Mexican native grows in the shade of trees in the wild so it’s happiest out of full sun. I particularly like the way the pink midribs of the leaf pick up the flowers. S. splendens, a tender native of Brazil found in high areas that stay warm throughout the year, is the red species that used to be grown from seed and bedded out in parks and gardens. There are more exciting forms with dusky flowers and they include the dark-maroon ‘Van Houttei’ and the purple ‘São Borja’. The latter, my personal favourite, is named after the city where it was found in Southern Brazil. S. splendens also prefers some shade and it’s not at all hardy, so treat this as you would pelargoniums. Take it in during winter and take cuttings (as an insurance against loss) preferably in July and August. Most I’ve mentioned can be acquired from Dyson’s Nurseries (01732 885094/www.great compgarden.co.uk), a salvia specialist. Robin Middleton, who has a private garden in Surrey, also runs an informative website (www.robinssalvias.com ) which has an extremely useful gallery of pictures. He began growing salvias 20 years ago and now has a private collection containing 100 species and cultivars, including some very rare and endangered species. He has built up a worldwide network of fellow salvia enthusiasts via the web. He has named several salvias and they include one which I adore called ‘Peter Vidgeon’, a hardy salvia which comes through in my garden even in terrible winters. The small pale-pink flowers do not fade in full sun and ‘Peter Vidgeon’ can flower all summer long, from June until November.

I was lucky enough to visit Robin Middleton’s garden last week and I was particularly taken with ‘Amistad’, a newish salvia with purple-blue flowers held in black calices. The flowering spikes, which produce flowers on one side only, are long and slender and the light-green foliage sets off the sultry flowers and dark stems really well. This lovely salvia was first spotted growing in a small nursery in Buenos Aires and was circulated among salvia enthusiasts. By 2005 it was appearing at trade shows in America and it can now be found in British garden centres. The dark calices and flower form indicate an allegiance to Salvia guaranitica, a species found in a wide area that includes Argentina and Brazil. In America, S. guaranitica is recommended for zones 8-11 and is hardy to 23 degrees. Gardeners in our area would almost certainly have to take it in.