Heavenly hydrangeas
Hydrangeas look their best now — but bring cheer even in winter
FLOWERING shrubs often look worn and shabby this month — but not mophead hydrangeas. Their lavish flowers can be as fresh as June roses. They’re versatile, too. You can naturalise them in woodland, place them as features or nurture young ones as houseplants. The finest I’ve seen this year line the courtyard of London’s V&A Museum. Their pink and violet mopheads were spectacular in July. If left untouched, those flowers will delight visitors for weeks to come.
For a gorgeous natural display, visit Cornwall’s Trebah gardens on the Helford River. From July to October the Hydrangea Valley is a rhapsody in blue.
Mophead hydrangeas originate from Japanese Hydrangea macrophylla and its Korean
relative H. serrata. The wild species have ‘lacecap’ blooms with showy florets encircling tiny fertile flowers. Garden forms come either with lacecap or rounded mophead blooms.
You can plant containerised hydrangeas at any time. They grow especially well in the damp, mild conditions of western Britain. Neutral or acid soils are better than thin sand or chalk.
You can grow them in large containers — if you re-pot regularly. Hydrangeas are thirsty, too, so keep them watered. With the best varieties, those beautiful heads should last for months. In a favourable autumn, the pinks or blues subside to greenish bronze, violet or dusky rose. Even in winter, the dry heads have an offbeat charm. IT’S wise to buy from specialist suppliers. Ashwood nurseries
(ashwoodnurseries.com) offer a super range including compact, pale blue Bodensee and white Schneeball whose flowers flush pink with age. For big blue mops, try Nikko Blue.
If novelties appeal, there’s a shocker whose mopheads show a mix of red, blue and green. I know this as Schloss Wackerbarth. T&M (thompson-morgan.
com) call it Glam Rock — though Punk would be more apt.
Flower colours are influenced by soil type. If alkaline, they can only be pink or white. Some may appear purple but never blue. In acid soils, flowers are blue or violet, but not the vivid pink. For blue flowers, apply a hydrangea colourant based on aluminium sulphate. Colourants are available, and work best, on pale varieties such as Vicomtesse de Vibraye. To keep potted hydrangeas blue, use ericaceous compost and rainwater.
To produce pink flowers on acid soil, apply lime. Remember that after liming, the soil will stay alkaline and that could compromise acid-loving plants.
LATE SUMMER GLORY
THERE’S no need to fuss too much about colour. Hydrangeas are lovely either way and is it not best for plants just to be healthy, whatever the hue?
To propagate, take cuttings now. Gather young shoots whose stems are on the point of turning woody. Stick these into pots filled with grit and potting compost, and leave them in a sheltered spot or a propagator.
When rooted, transfer to larger pots and keep those in a frame or under horticultural fleece. You can also raise hydrangeas as houseplants. Keep them watered and in a conservatory.
Prune mature outdoor hydrangeas in March. Leaving dead blossoms attached in winter will protect the tip buds which carry next summer’s first blooms. Besides, it’s pleasant to enjoy their gently declining beauty during the dark months.
SPOILT FOR CHOICE