What Kew’s resident expert, Richard Wilford, doesn’t know about alpines isn’t worth knowing. “We’ve got a very tall house to grow some very small plants,” he jokes. Wilford is an alpine lover and head of design and collection support at the Royal Botanic Gardens; its alpine house is a revolving door for alpines from around the world. Its soaring roof and graceful curves create a stack effect: as the air heats up, it rises, drawing cool air from the vents at the base of the greenhouse, so those tiny alpines believe they are in the high elevations of the mountains rather than on the alluvial plains of the Thames. Year-round, there’s always some tiny jewel to see: the plants don’t tend to live permanently in display houses, so it’s more have-your-turn-on-the-catwalk and then go backstage.
But you don’t need to head to the mountains, or to Kew, to enjoy alpines. With a little planning, you can grow them at home. They have a reputation for being high-maintenance, but they are surprisingly easy and hardy, and perfect for tricky corners and small plots. As their name suggests, alpines are from areas of high elevation, so they love full sun, cool roots and cold nights. Snow melt means there’s plenty of water in alpine areas, but it’s always rushing away through the rocky terrain, meaning the soil is very free-draining – nothing makes an alpine more unhappy than soggy, shady conditions. Also, these plants are small: exposed conditions, thin soils over rocky ground and cold temperatures mean they don’t tend to grow tall. Most reach barely 15cm, with many hugging the ground as tightly as they can to keep going.
Kew’s alpine house showcases some of the rarest and most difficult-to-grow alpines, but they sit among a much more easy-going lot which extend out into the rock garden. “Alpines have a reputation for being fiddly and hard to grow,” Wilford says. “The majority are really not complicated, and useful for awkward places such as walls, raised beds and banks. As long as they have drainage and sunshine, they’re happy.” His advice for creating the right drainage is blissfully simple: one-third grit or sand to the overall volume of soil. If it’s in the garden, just dig the grit into your soil; if it’s pot culture, mix one part grit to three parts soil.
In an average small garden, you can hardly start an arboretum or orchard, and you can’t own a collection of rampant perennials, but you could easily have a varied alpine collection. In fact, they are so suited to pot or container growing that you don’t even need a garden: a windswept balcony six floors up, or exposed roof garden, have a lot in common with mountain life, so perhaps it’s time alpines are liberated from their 70s cement trough and given a new lease of life. And they are certainly as cute as all those succulent houseplants so popular on Instagram.
Richard Wilford’s five easy alpines
Sempervivum will grow on sunny rocks, cracks in walls, and stony places. Put a little compost into the niches first, then nudge them in.
Alpine pinks Dianthus alpinus is a tiny mat-forming evergreen with bright pink flowers. It likes free-draining conditions and suits pots, gravel path edges and window boxes. D. alpinus ‘Joan’s Blood’ has dark crimson centres to the flower.
Erinus alpinus, or alpine balsam, forms neat rosettes of narrow leaves, and loves crevices. It has small pink or white flowers that appear well into summer.
Campanula cochlearifolia (fairy thimbles or ear leaf flowers), with its nodding blue flowers, comes from the mountains of central Europe. Keep its feet well drained.
Phlox douglasii is a low-growing perennial from the north-western US, where it grows in dry woodlands. It needs a dry winter, but good drainage and a sheltered spot by a wall will work. Flowers are purple, pink, pale lavender or magenta red.
