Hydrangeas – Popular Shrubs for the Garden
Most people think of hydrangeas as the shrubs with large mop-heads of, in blue or pink, often seen at their best in the gardens of seaside towns in late summer. These, the ‘hortensia’ varieties of Hydrangea macrophylla, are deservedly popular, as they flower well, look spectacular when in bloom and are not difficult to grow, succeeding in sun or semi-shade.
On chalk or lime the flowers of hydrangeas are pink or red and the colours are so pleasant that it is hardly worth going to the considerable trouble of trying to make them blue by adding ‘blueing’ powder or aluminium sulphate to thein considerable quantities at frequent intervals. On acid soils the flowers are blue while on neutral soils they may be either or both on the same shrub and, in fact, this may happen on fairly deep soils overlying chalk. There are a number of named varieties, in shades of pink and red, not all of them guaranteed to blue. There are also one or two white-flowered varieties.
A variation is the ‘Lace-cap’ hydrangea, with flat heads of flowers, large sterile florets surrounding small fertile florets. ‘Blue Wave’ is a fine variety and ‘Lanarth White’ always attracts attention.
Different in habit from all these, is Hydrangea petiolaris, the Climbing Hydrangea, a self-clinging climber, a most unusual plant for a wall of any aspect, or for growing up a tree.
Hydrangeas must have a moisture retaining soil otherwise the shrubs will flag noticeably in dry periods and look very sorry for themselves. Even then it may be necessary to give them a really thorough watering in periods of drought.
Pruning, where necessary, is done in April and consists of cutting away weak growths and frost-damaged wood.