A love of salvias
Growing up, salvias meant those garish red bedding plants (Salvia splendens) but decades later I have come to love this genus of flowers for its versatility, colour and pollinator benefits.
There are almost 1000 species in the Salvia genus, which is part of the sage (Lamiaceae) family. They are characterised by square stems, opposite leaves on the stem and many have a strong smell when their leaves are crushed. They range from shrubs and perennials to tender annuals and versatile herbs, such as sage (Salvia officinalis) and rosemary, which I must remember is now Salvia rosmarinus and not Rosmarinus officinalis. [It is so difficult to relearn names that you memorised decades ago - the old names just pop out!]
Clever pollination mechanism
Most salvias have flower spikes that rise above the foliage and their tubular flowers have a clever pollination mechanism that we see in all the labiates. If you look closely inside the flower, you will see two long stamens under the ‘hood’ of the flower with connective tissue that acts like a lever. When a bee or other pollinator lands on the lower lip and pushes into the tube of the flower to reach the nectar, the lever mechanism causes the stamens to move down and the anthers to touch the back of the insect and deposit some pollen. When the insect crawls away, the stamens return to their correct position to await the arrival of another pollinator. This is often described as the male stage flower as the stigma is not yet ready to receive pollen. The female stage is later to ensure cross pollination of the flowers.
Salvias in the UK are mostly pollinated by bees, but in the Americas they are also pollinated by hummingbirds!
Drought resilience
I like the fact that many of the salvias can be quite drought resilient and are commonly seen in Mediterranean style gardens. They show many adaptations to drought. If you look at the leaves of the common sage (Salvia officinalis) you will see that its leaves are covered in hairs, give a woolly appearance, and this helps to reduce water loss. This is achieved by the hairs creating a layer of still air around the leaf which reduces the rate at which water can transpire (evaporate).
Some of my salvias
Autumn sage
The autumn sage (Salvia greggii) is a bushy plant covered in flowers from summer through to autumn. There are lots of versions including Hot lips, Royal Bumble, Purple Queen etc. Native to Mexico, it loves a hot spot and copes well with heat and drought, but does likes a free draining soil. Mine have survived several cold winters in which temperatures have dipped to -10C. You can be ruthless with these plants in spring, cutting back hard to encourage fresh growth.
My tropical salvias
I grow several salvias from Central and South America – Salvia curviflora, S. confertiflora and S.involucrata. As you would expect, they are tender so are grown in large containers and overwintered in my greenhouse.
I find the young leaves of Salvia curviflora and S. involucrata to be really quite sticky and can trap small insects like whitefly, rather like the leaves of my sundews. This is due to the glands releasing oils. But as the plant matures through the growing season, this feature disappears, so may be its something to do with protecting young leaves? I love these salvia, they’re large, very showy plants, with flower spikes bearing pink flowers.
Salvia confertiflora from Brazil is a wonderful architectural plant with long flowering spikes of red/orange flowers.
Balkan clary
I have quiet a lot of the Balkan clary, Salvia nemorosa Cardonna, in my borders, to create drifts of blue through my thuggish yellow Phlomis. It’s a very hardy salvia with spikes of purple flowers. But this year was a disaster as virtually all my established clumps were eaten by slugs as the new shoots emerged in spring and I have heard the same story from many other gardeners. A few clumps proved to be very resilient and finally emerged and are just coming into flower, so I am glad I didn’t give up on them and haul them out. But others failed completely, so it’s been a replanting exercise. This time I have included a few Salvia nemorosa ‘Ostfriesland’ into the mix just in case it proves to be more slug resilient.
Mealy cup sage
Salvia farinacea Mystic Spires has to be my absolute top favourite salvia – as Cherish Finden of ‘Bake Off The Professionals’ would say: “Love, it, love it love it”. It has such a long flowering period, with spikes of deep blue flowers appearing in mid summer and continuing through to the frosts and it’s a total bee magnet. However, it’s not reliably hardy, so I dig mine up and overwinter them under cover to ensure extra large plants the following year. It’s also so easy to propagate (see below).
There is a larger version, Salvia farinacea Indigo Spires in gardens which is one I might try next year.
Alongside these, I have pots of the hybrid Salvia such as Amistad, Amante, and Love and Wishes which are moved under cover in winter. Some are 4 or 5 years old now and are quite substantial plants, filling their pots.
Propagating your salvias
I do a lot of salvia propagation to ensure a plentiful supply. Towards the end of the season, but before any frosts, I take many semi-woody cuttings. I have two methods. Some cuttings are pushed them into root trainers filled with a sandy soil mix and then popped into a large plastic container with a clear Perspex lid across the top to keep the humidity high. I also use large plastic containers which I half fill with the same sand/soil mix and push the cuttings into this and then pop on a Perspex cover. I don’t have drainage holes, so the moisture level is high.
I leave them until March/April so they are well established before transplanting to individual pots. Using these methods, I usually get 90% strike rate. I particularly like using the root trainers as its so easy to remove the rooted plant without damaging the roots.
That’s all for now
Happy gardening
Sally
PS
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Talks
Talk 13 September Talk by Sally at Yeo Valley Gardens, Organic September Celebrations, nr Bristol - you can book a ticket via the Yeo Valley website
Talk 21 September Sally is speaking to the Somerset Hardy Perennial Society, West Monkton, nr Taunton
Some very beautiful salvias I wasn't aware of, thank you
I didn’t realize Rosemary was part of the salvia family. Thank you! What a gorgeous garden. I write about gardening too. You can check it out here. https://open.substack.com/pub/pocketfulofprose/p/im-letting-go-of-my-garden?r=qqbxq&utm_campaign=post&utm_medium=w