The f lashy mob
Once, no trendy gardener would touch them, but now dahlias are back with a bang
THERE was a time when no selfrespecting horticulturalist would touch a dahlia with a dirty stick. These perennials were considered unrefined and tricky to maintain, with gaudy flowers that belonged to a bygone era.
Undoubtedly, this will come as a surprise to anyone who has taken up gardening in the past two decades. Over that period, dahlias have become highly desirable, and regarded as essential for injecting colour into gardens at the end of the growing season.
So how did these plants go from zero to hero? Much of the credit must go to the late Christopher Lloyd, who in 1994 planted several varieties in his exotic garden at Great Dixter in East Sussex. Among them was Dahlia ‘David Howard’, whose orange blooms are displayed against a foil of bronze-flushed leaves, and Dahlia ‘Bishop of Llandaff’, with scarlet flowers and purplish foliage.
Lloyd’s endorsement led to a revival of dahlias, especially those with bold flowers and dramatic dark foliage.
These days more than 1,500 varieties are available in Britain, boasting blooms in varying shades of white, pink, yellow, orange, red and purple. Some have striking two-tone petals or a contrasting boss of bright yellow anthers in the centre of each flower.
Originally from Mexico and parts of Central America, dahlias have been grown in Europe since the late 18th Century. The first three species – Dahlia coccinea, D. rosea and D. pinnata – arrived at the Royal Botanic Garden in Madrid back in 1788, where they were named in honour of Andreas Dahl, a Swedish botanist.
Plant breeding took off in the 19th Century, leading to ‘dahlia-mania’ across Britain. Among the enthusiasts was James Bateman, who created a tiered dahlia walk at Biddulph Grange in Staffordshire.
Dahlias were a staple of gardens during the 1950s, before plant fashions changed and they fell out of favour during the 1970s.
Their glamorous flowers have always been the main draw, but dahlias have the added bonus of attractive foliage – some even release a spicy scent on sunny days. Most are at their best right now, so there’s no better time to visit a garden famed for its late floral displays.
Make a note of your favourite varieties so that you can place an order with a mailorder nursery. Dormant tubers (a bulb-like structure) or rooted cuttings will be delivered from mid-winter onwards. Alternatively, browse through a catalogue.
You’ll find that dahlias are divided into ten groups based on the shape or structure of their flowers – single, waterlily, decorative, collerette, ball, pompom, cactus, semi-cactus, anemone, and a miscellaneous group for any that don’t fit into the others.
However, this classification is largely for the benefit of botanists and collectors. It can be a bit confusing for amateur gardeners, so my advice is simply not to worry about the technical stuff and to just buy those that suit your garden.
Among my favourite varieties are Dahlia ‘Jescot Julie’, known for its burnt-orange petals with a purple reverse, and dark purple ‘Summer Night’ (sometimes sold as ‘Nuit d’Été’). ‘Hillcrest Royal’ has cerise flowers with thin, spiky petals that perch on 4ft stems from July until the first frosts.
Lovers of dahlias with dark leaves should check out ‘Bishop of Dover’ with its white flowers displayed against brownish-purple foliage, and ‘Dark Desire’, whose blood-red blooms sit above clumps of bronze leaves. Growing to 3ft, ‘Karma Choc’ has black stems, purple-bronze foliage and deep crimson flowers that are the shape of a waterlily.
‘Giraffe’ is another stunning variety with tapering rose, cream and yellow variegated petals. I’ve also grown its close relation ‘Pink Giraffe’, which has the most exoticlooking pink and white striped flowers. Both types grow to about 2ft.
Pot-grown dahlias are available, but it’s cheaper to start your own from tubers. Plant individually into 5in pots in early spring, making sure they’re covered with a 1in layer of compost. Place on a windowsill or inside a frost-free greenhouse, then plant in a sunny spot when there’s no danger of frost.
Some nurseries supply rooted cuttings. Pot them up into 3in containers when they arrive, transplanting to 5in pots when roots appear through the holes at the base. Plant outside as before.
If you already have dahlias in your garden, they’ll need some attention in the next few weeks. After frost blackens the foliage, prise the tubers from the ground, clean off any soil and cut back growth to 6in.
Allow the tubers to dry indoors for four weeks before storing in seed trays filled with dry compost.
Those in milder parts of the country can risk leaving dahlias in the soil. Ensure they remain snug by covering the crown with a thick layer of compost – prevent the material from blowing away with a piece of wire mesh held down with stones.