In praise of the humble hydrangea

Hydrangeas in The Dell

One of the memorable sights of summer and early autumn at Bodnant Garden is the swathe of blue hydrangeas which light up the lush shade of the riverside in The Dell, along with the kaleidoscopic Liquorice Allsorts display lining Lily Terrace walls.

So often sniffed at as suburban stalwarts there’s no denying that, seen on mass, these huge, flamboyant flowers create an fantastic visual impact…well worth a double take.

Originally a foreign import, the hydrangea has become a staple in our gardens, now regarded as traditionally British as…rhododendrons…which aren’t British either! Among my own earliest memories are the big, blousy blooms which lined the path to my nan’s front door – as a child I couldn’t resist batting the flowerheads as I walked by, along with popping the fuchsia buds (sorry Nan.)

Sadly hydrangeas have suffered the same fate as their other exotic friends – that’s to say not being abused by small children, but their hardiness and dependability has made them such a common sight that they have pretty much lost their mystique. But it’s not all about the pom-poms. Aside from the ornamental displays on our Terraces, the shrubs dotted through The Dell and Shrub Borders give a glimpse of how the plants look in their native lands – in woods, scrabbling up rocky slopes and along riverbanks.

Trees, shrubs and climbers native to Asia and the Americas, hydrangeas have been around for longer than the people loving or hating them – the oldest fossil finds come from North America from 40 to 65 million years ago. In China and Japan hydrangeas have been cultivated for their ornamental value for thousands of years, while in North America they were used in medicine.

The first Hydrangea arborescens was introduced in England around 1736 from Pennsylvania by Peter Collison. A little later in 1788 explorer Sir Joseph Banks presented a Hydrangea macrophylla from Japan to Kew Gardens. Specimens continued to dribble into Europe but in 1879 the English nursery Veitch sent botanist Charles Maries to China and Japan and in the decades following, as planthunters were discovering new species abroad nurseries from Europe were introducing numerous cultivars to the market.

Today, there are known to be around 70 species of hydrangea. Here are some of the most notable you can see at Bodnant Garden:

Mophead Hydrangea macrophylla ‘Renate Steiniger’

The most common forms are Hydrangea macrophylla which produce characteristic blue, pink and purple flowers (most other species are white). They come in two types, the mopheads and the lacecaps, distinct by the shape of the blooms – the mopheads bear showy, dense, pompom-like blooms while the lacecaps have frothy heads made up of fertile flower buds in the centre surrounded by sterile blossom. Both have large, thick, toothed leaves, often heart-shaped.

Lacecap Hydrangea macrophylla ‘Blue Wave’

As they flower on wood produced the previous year it’s best to prune after flowering by cutting out one or two of the oldest stems at the base to encourage the production of new growth. However neglected plants can be renovated by cutting off all the stems at the base (though you’ll have to wait a year for it to flower). The dead flower heads are decorative in their own right and can be left on over winter, cutting back in spring.

Similar to the macrophylla (some botanists believe it to be a sub-species) is the Japanese Hydrangea serrata (Japanese Mountain Hydrangea) which produces neat shrubs with lacecap-type clusters of blue and pink flowers in summer and autumn. Like the macrophylla it flowers on old wood but because of its compact size and form needs little pruning.

hydrangea serrata 'Blue Bird' 

Above, H. serrata ‘Blue Bird’ and H. paniculata ‘Grandiflora’

One of the white forms is Hydrangea paniculata. Some of these are upright and some drooping in shape but they all bear cone shaped flowers, starting creamy white and turning shades of pale pink as they age in the autumn. The leaves are smaller, thinner, and rougher than leaves of the macrophyllas. The plants can be sprawling but they can be kept compact (and flower more profusely) if you cut back last year’s sideshoots to 5cm of the older wood in spring, keeping to a framework of branches.

Hydrangea arborescens ‘Annabelle’

Another lovely white hydrangea is the Hydrangea arborescens. Like macrophyllas they bear large lollipop-type blooms but the leaves of arborescens are generally thin, heart shaped, and not as stiff. Some flowers open green and turn white, then back to green again. Like Hydrangea paniculata, they can be pruned in spring back to pair of healthy buds to maintain a permanent framework.

Hydrangea quercifolia

Hydrangea quercifolia (Oak Leaved Hydrangea) gets its name from the shape of its beautiful large leaves which turn russet in the autumn. Again these hydrangeas open ivory, turning to pink as they age. Like macrophyllas they flower on old wood and to keep their informal shape need only minimal pruning in spring to remove old and rangey stems.

H.involucrata ‘Hortensis’

A smaller hydrangea is Hydrangea involucrata which has peony-shaped, pinky flowers that open late summer to autumn, with velvety leaves. They flower on new wood and can be pruned early in the year, though their size rarely makes it necessary.

Hydrangea aspera, villosa and sargentiana are tall, erect plants characterised by their furry foliage, and leaves which are the longest of all species, reaching as much as a foot in shade. They have large flat flower heads, usually pale pink and blue, and need little pruning, being more suited to informal settings.

 Hydrangea_petiolaris01

Above, H.aspera villosa and H.anomola petiolaris

And then there’s the climbing hydrangea Hydrangea anomola petiolaris a vigorous and sturdy plant which has creamy blooms and lacecap flowers in mid-summer. Long hanging shoots should be cut back after flowering and again spring to maintain a framework.

Hydangeas have become so popular because they are generally tough, suited to a range of situations, and reliably produce long lasting and eye catching displays. They last into autumn, changing colour wonderfully as they age, and even the seedheads and bare stems provide welcome structure to beds and borders in winter. Granted, the only thing missing is scent.

 Hydrangea macrophylla 'Altona' (2)

Ageing gracefully (and disgracefully) in winter

Achieving that Holy Grail of hydrangeas – the vivid blue – depends on your species and your soil type. White hydrangeas do not generally change colour but it is possible to change pinks to blues and vice-versa. If the soil is naturally acidic and contains aluminium the colour of the hydrangea will tend to be blue and purple. Aluminium sulfate may be added to the soil, and a fertilizer low in phosphorus and high in potassium may help too. Here at Bodnant Garden we’re lucky to have acidic soil, responsible for some amazing electric blues like the Hydrangea macrophylla ‘Renate Steiniger’ in our Shrub Borders.

Visually rewarding, hardy, versatile, long lived…what’s not to like? The right plant in the right place, or even in glorious abundance, the homely hydrangea has earned its place in out hearts and gardens.

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