A visit to Columbia Road flower market in east London has gone from a treat to a ritual; an hour, if early enough, to gorge on the colour and buzz of flowers. This famous Sunday market has a limited but reasonable supply of perennials, and there’s something about hot coffee and a bag loaded with plants that’s very pleasing.
It was here I found a little alpine clematis that I’d never heard of before called ‘Emerald Dream’. The label told me it had been bred in New Zealand, would grow no more than 60cm high and be filled with flowers through early spring. I didn’t know I needed a spring-flowering alpine clematis, but once I met it, I clearly did.
There are several types of spring-flowering clematis; the main ones are the rampant, large-leaved evergreen armand clematis (C. armandii), which flower in very late winter and early spring, and are entirely unsuited to pot life. You often see them spilling over fences with their white, scented flowers seeking the sun – much to the owner’s chagrin, one imagines.
The other lot are part of the Atragene group that are found high up in chilly mountainous areas in Europe and Asia, and have lantern-like hanging flowers, including C. alpina, C. macropetala , C. koreana and C. chinensis. They can take cold weather and are different from summer-flowering clematis in that they dislike being planted too deeply in rich soil. This lot grow out of rocky places and thus have a fine, fibrous root system that prefers poorer, free-draining soil rather than the usual enriched stuff you give other clematis. They hate to be waterlogged, so add grit or sand. They grow to about 2.5m tall, making them perfect for containers and pots, or in the ground covering fences. They hate to be pruned hard; if you do need to prune, do so after flowering, removing dead or damaged stems.
C. alpina ‘Francis Rivis’ is sky blue, ‘Jacqueline du Pré’ is pink and ‘White Columbine’ is pure white, like crumpled tissue. C. koreana ‘Amber’ is a hybrid with soft yellow double flowers that look like knickerbockers. It flowers in May and June, and there’s a second flush in September.
There are a number of C. forsteri group hybrids that have flooded the market recently, and this is where ‘Emerald Dream’ comes in. These have been bred in New Zealand, often a cross between the alpine, evergreen marbled clematis (C. marmoraria) and C. forsteri. They will rot off if kept wet in winter and need free-draining compost, so add at least 50% grit to the pot and give them full sun, if possible. ‘Pixie’ has lovely citrus-scented flowers and grows to no more than 25cm high, perfect for a windy balcony or window box. ‘Emerald Dream’ has greenish-white flowers from April to May.
If you can’t get to Columbia Road, mail order is the answer: Thorncroft Clematis Nursery online is well worth a visit.
