THESUPER IT’S SALVIA!
Trouble-free and bearing silky purple flowers on 6ft stems – there’s no wonder salvia ‘Amistad’ is starting to grow on us, says Monty Don
FOR the past 25 years I have used Salvia guaranitica ‘Blue Enigma’ as a mainstay of our Jewel Garden, where its violet flowers are central to the late summer display. In fact, I am using the wrong tense. It used to be central, but for the past few years it has hardly performed at all, growing perfectly strongly but sullenly refusing to produce flowers save for the odd reluctant bloom late in the season. I put this down to climate change, with our cooler and wetter summers failing to ripen the new growth sufficiently to allow it to produce buds and flowers. It’s a big loss.
But one door closes and another opens. There is a (relatively) new salvia called ‘Amistad’ that is storming our gardens in a rich purple fanfare of colour, regardless of the weather. It’s undoubtedly a superlative plant, growing pretty much trouble-free in most soils as long as it gets some sun. The silky purple flowers gleam out from chocolate sepals and, at the time of writing, are flowering on stems six or seven feet tall, more profusely than ever even though it has been doing so since July. I don’t treat it as hardy although I suspect it will survive a few degrees of frost if your soil is well drained. As with so many plants from near the equator, the combination of cold weather and wet soil is the killer.
No one seems to know where ‘Amistad’ originated but most agree it was first seen in 2005 and is an Argentinian hybrid between S. guaranitica and another, unknown species. If it’s in a pot then bring it in before the first hard frost and, once protected, keep it on the dry side. Cut it back as much as needed to fit the available space but not too hard as it’s better to do the final prune in spring when you can see where the new growth is coming from and cut accordingly.
If you grow it in a border then either mulch it very thickly and don’t cut it back at all if your garden is well protected or, as I do, dig it up and pot it into a temporary container for the winter, treating it in the same way as the permanently containerised specimens. It’s also a good plan to take some cuttings from the side shoots, which root easily in a free-draining compost in a greenhouse or windowsill and can be potted on in the spring.
If you want a true blue salvia then Salvia patens is your best option. I grow ‘Cambridge Blue’ which works perfectly with the paler pastel shades in my Cottage Garden borders. It can either be grown as a herbaceous perennial and will die right back each year to reappear in spring – or else as a herbaceous annual, which is a better bet if you have heavy, cold soil.
It also forms tuberous roots, and these can be lifted and stored just like dahlia tubers. It’s important not to let the tubers dry out and they are best stored in leaf mould or vermiculite, watered lightly and re-dampened every few weeks. They can then be potted up and grown in a greenhouse from mid-February, dividing the tubers to increase the plants.
I have another non-flowering salvia that grows lustily every year, the foliage smelling deliciously of pineapple when crushed in your fingers. I say ‘non-flowering’ but Salvia elegans will produce its flowers about now and get to its very best in December, with a furious display of crimson flowers – but only within the protection of a heated greenhouse, because its flowers come so late they invariably coincide with the arrival of the first snap of cold weather that cuts them to shrivelled rags overnight. n ÷Monty’s new book, Down To Earth: Gardening Wisdom, is published by DK, priced €25.20 from Easons (www.easons.com).