It is hard to think of another summer flowering shrub that blooms as long as the shrubby members of the salvia family. Salvia microphylla – the most winter-hardy of the shrubby species – begins to flower in May and continues to flower, continuing to do so until at least October, if not well into November.
But there’s a catch: These salvias are not completely winter hardy and gardeners in colder parts of the country will be taking a gamble that they will survive the winter. But for a potential return of up to seven months of flowers, growing a shrubby salvia is certainly a gamble worth taking.
“Give them a chance,” urges Plant Heritage National Collection holder of salvia species, Lynsey Pink. “A lot of growers don’t test plants like they used to, so some of the newer varieties are riskier. Start with cultivars that have been around for a while, because they’ve stood the test of time.”
Salvia ‘Hot Lips’ | Photo credit: Shutterstock
Consider ‘Hot Lips’, the popular cultivar with columnar red and white flowers that grows to about 1 m tall. This form of Salvia microphylla was discovered growing wild in Mexico and is as tough as these salvias come, hardy in most areas as long as it is grown in soil with excellent drainage – it is wet around the roots, which often kills these shrubs in winter. The bicolored flowers sometimes change depending on the weather. During a hot summer they may turn completely red or completely white, but they return to red and white as the weather cools in fall. Other ‘Lips’ have since been introduced, including the purple ‘Amethyst Lips’ and the pink ‘Cherry Lips’.
“More Salvia microphylla “The harder a cultivar is to grow, the harder it is,” says Lynsey, who has been tending her collection of salvias in her garden in Fareham since 2001. ‘Moth’ is her favourite, with velvety flowers in a rich, jewel-like shade of purple-red. At 75cm tall, it is also hardy in most of the country, provided it is well-drained. ‘Royal Bumble’ is also on her must-have list, for its bright red flowers, as is ‘Cerro Potosí’. With its bright red flowers, this much-admired cultivar is a regular fixture in many gardens. “It’s very good,” confirms Lynsey, “and its shoots can grow underground, so it wanders around on its own.” Not many cultivars of Salvia microphylla send out shoots in this way. When they do, however, the shoots act as insurance: if the upper growth were to be hit by frost, the underground shoots would survive.
Salvia ‘Nachtvlinder’ | Photo credit: Shutterstock
‘Wild Watermelon’ was discovered on the same Mexican mountain as ‘Cerro Potosí’. It has dark pink flowers with a delicate brushstroke of white in the throat of the flowers. ‘Pink Blush’ is more of a rose pink, while ‘Silas Dyson’ is a deep wine red. Pinch out the tops regularly to maintain a bushy growth habit. Even darker is ‘Purple Queen’, a rich purple-blue.
In addition to light, well-drained soil, all Salvia microphylla species require a sunny spot. They are very drought tolerant, so are a good choice in areas with low rainfall. They all have soft, medium green leaves that are aromatic and smell strongly of blackcurrant when crushed. They all have a bushy growth habit, with most growing to between 75cm and 1-1.2m tall – perfect for small spaces. If there are any doubts about the soil or whether they will survive the winter, follow Lynsey’s lead and take copious cuttings. “The first thing I do when I get a new plant is propagate it,” she says. “Take cuttings so you have a backup if you lose it.” Luckily, these salvias root easily, so take cuttings and growing more plants is a simple process.
Salvia ‘Royal Bumble’ | Photo credit: Shutterstock
The other common shrubby species is Salvia greggii. Also native to Mexico, it has similarly shaped flowers, but Lynsey finds it harder to keep them through the winter. That hasn’t stopped S. greggii ‘Peach’ finds its way to her affections, with its peachy orange flowers. Take cuttings every year, as it can be short-lived. ‘Stormy Pink’ is another good S. greggii cultivar: flowers in the colour of pink sugar mice, with contrasting dark purple calyxes and stems. Completely different is S. greggii ‘Sungold’, with light yellow primrose flowers.
In Mexico there are shrubs of Salvia microphylla And S. greggii hybridize naturally, and the resulting hybrids are called Sage X jamensisThese hybrids have produced some beautiful, long-flowering shrubs suitable for the garden, including another Lynsey favourite, ‘Peter Vidgeon’, which has won an RHS Award of Garden Merit. It was bred by salvia enthusiast and collector Robin Middleton. Lynsey also recommends Salvia x jamensis ‘Heatwave Glimmer’, a creamy white plant with dark stems.
Salvia ‘Amethyst Lips’ | Photo credit: Shutterstock
Don’t give up on growing shrubby salvias if your soil is heavy and wet, or if you live in a cold spot. Salvias are grown in containers of well-draining compost (a mixture of soil-based John Innes No 3 and multi-purpose compost with around 15% horticultural grit is perfect) and can then be moved to spend the winter in a cold or frost-free greenhouse or in the shelter of a wall where they can be sheltered from the worst of the weather. “There’s a lot you can do to help them survive the winter,” says Lynsey, “and they flower for so long it’s worth the effort.”
• Plant these salvias in light, well-drained soil in full sun. In colder parts of the country, find a sheltered spot, such as next to a sunny, south-facing wall.
• Salvias don’t need overly rich soil, but they do benefit from a little fertilizer in the spring. “We put a little granulated chicken manure around the base of the plants in the spring to give them a boost of growth,” says Lynsey.
• Plant shrubby salvias in spring, after the last frost, so they have the longest possible period to establish their roots before winter sets in. Plants bought later in the year or in autumn are better left to overwinter in their pots in a frost-free place and planted out in spring.
• Don’t prune the top growth of shrubby salvias until at least late March, and not when frost is forecast. Wait until new green shoots have emerged before cutting back (as you would prune a hardy fuchsia). If you don’t wait, “you’re essentially sending it to its death,” Lynsey warns.
• Some salvia growers recommend a second pruning – the hampton hack – carried out in early July during the Hampton Court Flower Show. This keeps the bushes more compact, but at the expense of flowers for three to four weeks.
• Take cuttings as insurance. Salvia greggii Cuttings should be taken in early summer, advises Lynsey, but Salvia microphylla will root readily at any time during the growing season. Use a gritty cutting compost and take 8cm long cuttings from shoot tips, stripped of their lower leaves. Pot up as soon as they have rooted and overwinter for planting in spring.
