HYDRANGEA MACROPHYLLA

Hydrangea macrophylla

The popular garden species Hydrangea macrophylla is name which covers a large and varied group of hydrangeas, many of which are possibly of hybrid origin. They can be divided into two groups, namely the Hortensias and the Lacecaps. The original species is native to both China and Japan, and in the United Kingdom will come into bloom from July to September.

They have an average height of between 1.2 and 1.8 metres in most garden environments. In sheltered gardens and woodlands it is possible for them to achieve a larger height of approximately 3.5 metres. They are particularly suitable for coastal planting.

Hydrangea macrophylla forms will perform best in  a good loamy soil that is moisture retentive and has been previously enriched with well-rotted farm manure and garden compost. They will prefer a sheltered position in either full sun or partial shade. Avoid areas where they will receive early morning sun as this can cause damage to new growth after night frosts.

Hydrangea macrophylla 'Endless Summer'

In very shallow chalk soils Hydrangea macrophylla and its forms can become chlorotic (a condition in which leaves produce insufficient chlorophyll producing leaves which are pale, yellow, or yellow-white), however this can be counteracted by generous feeding and mulching. In alkaline soils it is impossible to maintain the blue coloured blooms without additional treatment - usually the application of Aluminium sulphate (often called 'bluing powder'). It is easy to stabilize the blue pigmentations of container grown specimens and those in soils which are only slightly alkaline. Where its use is desirable bluing powder should be applied every seven to fourteen days during the growing season at a rate of 85 grams being dissolved in 13.5 litres of water.

Hortensias

This group covers the familiar mop-head hydrangeas. The florets are sterile, forming large globular heads of white, pink, red or blue or even a combination of these colours. In some cultivars this can produce a gorgeous and almost metallic sheen.

Lacecaps

This is a smaller group to the Hortensias, but are similar in growth and and requirements. They produce large flattened corymbs of fertile flowers, around which are borne a ring of coloured ray-florets.

Pruning

This out and cut back immediately after flowering (except in colder, northern regions). Prune old flowering shoots to within a few centimetres of the old wood.

For related articles click onto the following links:

HYDRANGEA QUERCIFOLIA
HYDRANGEA SARGENTIANA
HYDRANGEA SERRATA 'Bluebird'
WHY HAS MY BLUE HYDRANGEA TURNED PINK?