10 AGM hydrangeas

Hydrangeas

Words: Graham Rice

Hydrangeas combine two features valued by almost all gardeners. Their bold flower heads and their impressive colour create a long-season impact from a modestly sized plant that is matched by no other deciduous shrubs. On top of that, hydrangeas are amongst the most robust of shrubs, putting on a good display in most rich soils or poor.

Of course, hydrangeas prefer fertile soil but seem remarkably tolerant of minimal care especially if their site is prepared well before planting. On acid soil, remember, the flowers of many tend to be blue, and pink on lime. Many hydrangeas also make good dried flowers, either cut for indoors or left on the plant. Here’s my selection of a range of hydrangeas which have received the AGM.

Hydrangea arborescens ‘Annabelle’
The huge not-quite-spherical flowerheads of ‘Annabelle’ can be 20cm (8in) or sometimes even 25cm (10in) across. The harder you prune – you can cut the plant down to the ground in spring if you like – the larger the flowerheads will be. Opening from mid-July in pale green, the flowers mature through cream to pure white and then back to pale green in October. Happy in light shade. 0.9-1.8m (3-6ft)
 

Hydrangea aspera
Villosa Group
Making a much larger plant that my other choices, the highlight is the August and September display of large lacecap flowerheads 15-20cm (6-8in) across; the large outer florets open in pink but soon mature to blue while the mass of small inner florets are blue and develop purplish tones. More refined in its foliage than other forms of H. aspera, the leaves have pink veins on the underside. Retains its blue coloring on limey soil. 2.4-3m (8-10ft)

Hydrangea macrophylla ‘Ami Pasquier’
A mophead variety with reddish pink, sometimes bright red or almost crimson flowers on alkaline soils; on acid soil the colour tends to be more of a wine-purple shade than blue. One of the hydrangeas first to bloom, flowering begins in early July and continues to late August and beyond. Although the flowerheads are just 10cm (4in), the plants are vigorous and productive. Developed in France and introduced in 1930. 1.2m (4ft)
 

Hydrangea macrophylla ‘Générale Vicomtesse de Vibraye’
The heads of this free flowering French mophead, introduced back in 1909, are so crowded with florets that the edges are squeezed together. In fact, if the plant is cut back hard the resulting flowerheads will be so large they will bend over and touch the ground under the weight of rain. So lighter pruning is advisable. The flowers age to limey green and are good for drying. 1.5-1.8m (5-6ft)
 

Hydrangea macrophylla ‘Lanarth White’
One of the best of all lacecaps, and also one of the best hydrangeas for exposed positions, poor soil and by the sea. Blooming from early July to the end of August and beyond, a ring of large pure white florets surrounds a mass of green buds which open to pale blue or lilac. Each sterile white floret may have a pink or purplish fertile floret in the centre. Dries well to cream, almost yellow in the centre. 1.2m (4ft)
 

Hydrangea macrophylla ‘Madame Emile Mouillère’
The large 20cm (8in) flowerheads of this old French variety, another from 1909, are distinctive in being so crowded that the individual florets are compressed together but also reveal a touch of elegance as the edges of each floret are prettily serrated. Best out of direct sun, the heads can be weighed down by heavy rain. The pure white flowers open in July, continue well into the autumn and age to palest pink or lime green. 1.8m (6ft)
 

Hydrangea macrophylla ‘Veitchii’
Imported from Japan way in the 1860s, this white lacecap has florets faintly blushed with lilac which age to lime green before folding down late in the season to reveal their reddish brown backs. The mass of fertile central flowers are pink in bud then open to blue on acid soil, or remain pink on lime. At their peak from mid July to mid August, the 20cm (8in) heads dry well for the winter. 1.5-1.8m (5-6ft)
 

Hydrangea paniculata ‘Limelight’
The recent RHS trial proved that many of the varieties of H. paniculata are superb garden plants and ‘Limelight’ is one of the best. 'Distinct and outstanding, stunning lime-green flowers' was the overall verdict. This tough, rather upright variety flowers from mid July to early October, the lime green flowers becoming darker with age and finally to develop pinkish tints. Prune back to four buds in March for the best display. 1.65m (5^1/₂ ft)

Hydrangea paniculata Pinky-Winky (‘Dvppinky’)
Pinky-Winky is one of the best suited to small gardens. Blooming from early August to early October, the flowers open in lime green, develop yellow tints as they age, and mature to deepest pink; they often reveal all the colours in one spike, the effect enhanced by red stems. The flowers also have a spicy fragrance. Flowering time can easily be controlled by hard pruning (late flowers) or dead-heading only (early flowers). 1.4m (4^1/₂ft)

Hydrangea serrata ‘Bluebird’
Combining colourful flowers and colourful autumn foliage, this old Japanese variety features 15-17cm (6-7in) lacecap flowers with pink or blue outer and inner florets, depending on the soil. They open from early July until well into the autumn. As the fertile florets are fertilised, the colourful outer ones bend over to reveal the bright pink colouring on their backs – whatever the soil. 1.5m (5ft)