In sunshine or shade, flamboyant hydrangeas will make your garden glow
with their flamboyant flower heads in lush blue, pink or white, hydrangeas are among the signature blooms of the summertime garden. Traditionally a shrub for shady garden beds or side paths, hydrangeas have spread their wings during recent years, with a bunch of new, sun-loving varieties appearing on the scene. And they’ve scaled down a little in size, too, meaning they now make great container plants for decks and patios. So, if you don’t have hydrangeas in your garden, you’re missing out on one of the best summer flower shows going around. Check out the beauties here and be inspired! ➤
1 The voluptuous blooms of mophead hydrangeas vary from blue to pink in colour, depending on the ph of the soil. Sometimes, you’ll even get subtle shades of both on the one plant!
2 The blooms of double-flowered hydrangeas have lots more petals – they make gorgeous cut flowers.
MEET THE FAMILY
The best known hydrangeas are the mophead varieties
(Hydrangea macrophylla), which are deciduous shrubs growing to about 1-2m in height and bearing large rounded flower heads. Lacecap hydrangeas are a smaller group (belonging to the same species), which have more flattened flower heads, where the showy coloured petals form a ring around a cluster of tiny flowers in the centre.
Hydrangea paniculata, which is native to China and Japan, produces large panicles of flowers on a robust shrub, growing to about 4m in height, and is more tolerant of sun. New forms include ‘Candlelight’ and ‘Diamond Rouge’, both of which will grow in full sun or part shade.
The oak-leaf hydrangea
(Hydrangea quercifolia) is another lovely form, which is native to the US. It features deeply lobed leaves, which turn fabulous red shades in autumn, and produces creamy white cone-shaped flowers in summer.
3 In garden situations, hydrangeas look great planted as loose hedges – you can trim them back in autumn, once the flowers have faded.
Hydrangea macrophylla varieties are known for their habit of changing flower colour, according to the ph of the soil they're growing in. Acidic soils (below ph 7) produce blue blooms and alkaline soils (above ph 7) produce pink. If you’re desperate to change the colour, there are bluing or pinking tonics available. However, the best advice is to just enjoy the flower colour your soil produces, rather than trying to radically alter its ph level – which might also have a negative effect on other plants. Alternatively, consider growing plants in containers and you’ll have total control of the soil conditions. The flowers of white hydrangeas are not affected by the ph of the soil. ➤
Sun-loving hydrangeas For sunny areas of the garden, choose forms of Hydrangea paniculata, which are more sun-tolerant. ‘Candlelight’ bears creamy white flowers which turn pink as they age, while ‘Diamond Rouge’ produces white flowers in summer, which gradually morph through pink to rich red.
One of the newest hydrangeas to appear on the market is ‘Magical Revolution’, which produces classic mopheadstyle flowers with a unique quality – they last for up to 150 days! Opening in spring, the blooms go through a colour transformation from pastel blue or pink, through pinky-red shades and onto deep burgundy by autumn. They’re also compact growing plants, so are perfect for pots and small gardens, too.
The Endless Summer range of hydrangeas also offers a long-flowering season in the garden, since the plants flower on both old and new wood. The plants can be pruned back all over, and will bloom again in about 8-9 weeks.
For hydrangea blooms with a twist, seek out some of the double-flowered forms. The You & Me Series, from PMA, features a range of gorgeous double-flowered cultivars, including ‘Desire’, ‘Forever’ and ‘Romance’. Growing to about 80cm high, they’re ideal for tubs and containers in partly shaded gardens or courtyards.
HOW TO GROW THEM
Position Mophead hydrangeas grow best in filtered shade, or else a combination of morning sun and afternoon shade. They won’t thrive in heavy all-day shade, especially where there is no air movement around their leaves, as this can lead to problems such as powdery mildew. Hydrangea quercifolia and H. paniculata both tolerate more sun – just avoid positions that are blasted by hot westerly afternoon sun in summer.
Soil Hydrangeas thrive in organically rich soil, so dig in additional compost and cow manure at planting. They also love moisture, so add waterretaining crystals to the soil as you backfill. After planting, mulch the surface of the soil to a depth of about 3-5cm.
Maintenance Feed plants in early spring, with a dose of controlled-release fertiliser or manure pellets. This will give them plenty of nutrients to draw on while forming the flowers. Top up the mulch layer in late spring or early summer and, once the plants are in bloom, feed them with occasional doses of a soluble fertiliser, using a flower and fruit formulation.
Pruning Prune shrubs back in autumn or winter, only cutting back the stems that flowered during the summer. Make the cut just above a pair of plump buds.
GROW YOUR OWN
Hydrangeas are easy to grow from cuttings taken during the spring or summer months. Take tip cuttings about 10-15cm long, making the cut just below a pair of leaves. Remove this bottom pair of leaves, then cut the remaining leaves in half, to reduce water loss. Plant the cuttings into pots filled with propagating mix and place in a shady but bright spot. Don’t let the soil dry out, keeping it just damp but not waterlogged.
Cerise mophead hydrangea
‘Magical Revolution’ ‘Romance’ ‘Candlelight’ ‘Diamond Rouge’
Two-tone varieties have a white eye at the centre of each flower. SOURCES ‘Candlelight’, ‘Diamond Rouge’, ‘Magical Revolution’ and the You & Me Series of hydrangeas from Plants Management Australia (pma.com.au). Endless Summer range from Fleming’s Nurseries (flemings.com.au).