It’s always a thrill to visit the national collection of a plant. These growers might be the trainspotters of the horticultural world, but for those of us who care about plants, they do important, painstaking work – preserving, propagating and documenting a particular group, and by so doing, conserving plant heritage and preventing cultivars from dying out.
In the case of dahlias, which have come in and out of fashion more regularly than platform shoes and mini skirts, the years in the wilderness when they were derided as the height of suburban vulgarity, could easily have meant the loss of many cultivars.
So a wander through the beds of the 1600 varieties grown at the National Collection near Penzance in Cornwall, is a revelation. The first thing that hits you, even on a drab day in August, is the carnival of colour, one of the things that the late Christopher Lloyd, creator of Great Dixter garden in Sussex, who always championed dahlias, prized about them. Here brilliant yellow clashes with pink and scarlet with apricot. Then there are the shapes: pompom, waterlily, cactus, orchid, peony – from uptight, pencil-skirted waltzers to flamboyant glowstick ravers.
These are some of my favourites: Emory Paul, (below right) classified as formal decorative, dark pink, blowsy and the size of a dinner plate, Quel Diable, semi cactus, blazing orange; the twin clergy with their black, cut leaves contrasting with bright flowers – Bishop of Llandaff (peony, scarlet) and Bishop of Canterbury (below left) (single, magenta) and finally, Black Monarch (above, right) (decorative, dark blood-wine red).
Yet they are a labour of love. They hate sitting in water, so it’s a risk leaving the tubers in the ground over winter. And even if you do, slugs are likely to munch on the new shoots as they emerge underground in spring. But if you have time, patience and a handy dry cellar, the national collection’s website tells you all you need to know. https://nationaldahliacollection.co.uk/growing-tips/tubers-getting-started/.
If, like me, you don’t have space to grow them, just be glad they are back in vogue. And try to get to Cornwall.