Monday, 11 October 2010

Late salvias



Opinions are divided on the late-flowering species of Salvia: some think they're wonderful and can't have too many, while others regard them as a waste of space, flowering too late to be of real value and requiring too much in the way of overwintering care to make them worthwhile. This is a coin that can be viewed from both sides: last year an early frost robbed us of their display, but the mild weather we are currently enjoying is allowing them to make a really useful contribution to the garden.

As usual, I think it is down to being selective, and choosing to grow species and cultivars that can be relied upon to perform in one's own conditions, always trying new things along the way. Two that I have grown this year for the first time are the well-known 'Indigo Spires' (top) and a clone smuggled back from South Africa by a friend. This has shot up to head-height, and in the cottage garden is currently thinking about expanding small inflorescences of purple bracts and flowers: against a wall at Colesbourne Park there are actually two or three flowers open (right). It may be lovely in South Africa, or in a conservatory, but I'm afraid my plants are being left out for hardiness testing: here it is not worth the space or trouble to keep it growing through the winter. 'Indigo Spires', on the other hand, is superb, and I can't imagine how I managed without it in the past. It has looked good most of the summer, and is now combining well with Helianthus 'Lemon Queen': earlier in the season Scabiosa columbaria subsp. ochroleuca entwined through it made a very pretty sight.

Salvia haenkei 'Prawn Chorus'

Salvia is one of a handful of genera to have flowers in all three primary colours, enabling different species to appear in many different garden combinations. The red and orange flowered species are particularly valuable at this time of year, when they glow in the low-angled sunshine. A relatively recent introduction is Salvia haenkei 'Prawn Chorus', apparently a compact selection of a large and sprawling Bolivian species. Whoever gave its name was inspired, as the flowers do suggest miniature prawns standing on their tails: in the wild they would be pollinated by hummingbirds. So, presumably, are the stubby flowers of S. confertiflora (left, with Kniphofia 'CoolKnip'), appearing from russet-velvet calyces on long inflorescences. This is one of the plants that I sometimes think isn't worth the trouble to grow, as it gets larger and leafier through the summer before the flowers appear, but I always repent and ensure there are cuttings in for the winter. Now, when it is flowering well, there are no such thoughts to entertain.

Also with furry calyces, but even more chenille-like, is Salvia leucantha (above). This Mexican species is a low-growing shrub, producing narrow, white-backed leaves, and, late in the season, the arching inflorescences of purple-furred buds. Where it is perennial these appear over a long season, but here they need the weather to be kind to achieve full potential, usually managing about a couple of weeks before being ruined by frost.  The corolla is usually white, but is sometimes purple, as in the clone grown here, probably that known as 'Midnight'.  Although the species mentioned above are all tender, there are some excellent hardy species of Latin American salvias (in addition to the more generally hardy shrubby species and cultivars allied to S. microphylla). Among these are the familiar blue S. uliginosa and S. guaranitica, but also the tall, robust S. atrocyanea. This is a totally hardy plant here and looks well at the back of the border, where the many stout flowering branches are covered in blue flowers emerging from green bracts. It also starts in August, so has a good long flowering season.

Salvia atrocyanea

All these salvias are easily propagated from cuttings, though it is always rather annoying that you have to take the tips of shoots that should bear flowers a few weeks down the line. I like to get them taken while it is still warm in August, as they then root very quickly and well, potting them up (into 7 cm pots, to save space) as early as possible in September so that their roots are established in the pot before warm weather fades. If this isn't possible I prefer to leave a crowded pot of cuttings to overwinter without disturbance. This is preferable to having a young plant loose in a pot of damp compost all winter, I feel: they soon burgeon into growth in spring.  Although it is perhaps a little late I have potted up this year's crop of cuttings today (right), counting on the continued mild forecast to get them settled and growing well before the weather turns.
Salvia fulgens 'snake': the stigma protrudes from the upper lip.

3 comments:

  1. I have mixed views about Salvias and I agree that the late flowering ones are so dependent on the weather but at least this year they have had the opportunity to perform

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  2. John
    Enjoyed the Salvias piece. My own favourite is S.Discolor; silvery foliage, sticky stems, really black flowers and oh that scent!
    Steve Owen

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  3. I know this is an old post, but google for something salvia related this came up and I am totally intrigued with Salvia haenkei 'Prawn Chorus' - might have to try and get hold of that one! (Mind you, I do love Salvias!)
    Very interesting post John.
    K

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