This monthâ€™s featured plant is Cotinus, a genus of two species. The other species is the Rhus plant, now a separate plant listed botanically.They are often commonly referred to by their other name of â€˜Smoke Treesâ€™ in recognition of their attractive dark smoky purple blue foliage in late summer. One of the most attractive of the larger flowering shrubs, many of the varieties have rich autumn tints on their leaves.
The plants are found growing in the wild in rocky habitats, from the Mediterranean regions to China and also in Southern United States of America. They thrive best in reasonably fertile, moist, but well drained soil in full sun or partial shade. The darker purple leaved forms, such as Nottcutt, pictured above and Royal Purple, pictured here, colour best in full sun.
Pruning should be carried out in early spring in this part of Scotland. For best results with the larger leaved varieties, cut back vigorously to within 2-3 buds from ground level, followed by a generous mulch of well rotted farmyard manure to compensate for the loss of vigorous wood.
Cotinus can be propagated by three methods:
1 From seed sown in containers in a cold frame in autumn
2 From layered branches, pegged down in mid spring
3 From rooted softwood cuttings taken in summer. Use either a propagator or a 5″-6″ pot, covered with a loose â€˜tentâ€™ of milky white polythene.
Most varieties will eventually attain a height of 2 metres or more in ten years.
Some varieties to try are:
Coggygria â€˜Flameâ€™, pictured below, one of the best forms for its rich, orange-red change in foliage
Coggygria â€˜Graceâ€™, a bushy, vigorous shrub with oval, purple leaves, turning brilliant red in late autumn
Coggygria Follis Purpureus, rich, plum purple coloured leaves, changing to light red shades in autumn
Coggygria â€˜Royal Purpleâ€™, deep wine purple leaves, reddening towards autumn
Coggygria â€˜Golden Spiritâ€™, beautiful, soft, golden leaves from spring through to autumn
Coggygria Purpureus â€˜Burning Bushâ€™, leaves are green with large panicles of purple grey flowers, which resemble puffs of pink smoke from a distance
Cotinus Obovatus, the rare American species which, in favourable seasons and situations, is one of the most brilliantly coloured autumn shrubs. Pinkish bronze leaves when young, turning brilliant orange, red and purple in autumn. Hard to find!