Few shrubs are as popular – and as showy – as the Hydrangea. There are several types: the common mophead or hortensia types, and the equally attractive lacecaps, together with others of upright or climbing habit. Many of the mopheads – which all have generally large, rounded flowerheads – have blue flowers when grown on an acid soil, and pink flowers when grown on an alkaline or chalky soil. Lacecap hydrangeas are instantly recognisable: they have flattish flowerheads comprising a centre of tiny, clustered flowers surrounded by a ring of showy florets.

Hydrangea cultivars with white flowers are unaffected regarding soil type, but they do prefer a spot in part-shade (in full sun they are prone to take on a reddish tinge).

One of the most breathtaking of large shrubs, Hydrangea paniculata ‘Grandiflora’ cannot fail to grab one’s attention as it erupts from the back of a border. Its large conical sprays of flowers, which start off pale green, then cream, and then slowly become flushed with pink in full sun, resemble huge lilac blossoms in shape. Many wonderful new cultivars of Hydrangea paniculata have been developed.

The climbing hortensia (Hydrangea petiolaris) is self-clinging, and can climb a wall reaching as much as 20m / 60ft under ideal conditions. However, it is easily pruned and kept under control. It is ideal for a sunless, north-facing wall. So many hydrangeas have been bred in the past two decades, mostly in Japan, to give us very many different colours and shades, from deep maroons to pale greens, and often with two or three contrasting colours in the flowerheads.

Ideally, hydrangeas prefer sheltered positions in part-shade. They only need pruning to restrict their size, if they are growing too large for their site, and this should be carried out in late winter.