Hydrangeas are grown for their long-lasting flowers, but these northern hemisphere plants vary in their needs, so careful choices need to be made.
The most common, Hydrangea macrophylla, is a Japanese native used to a summer soaking in their rainy season, so it's not for dry gardens.
If you have a dry garden, opt for a North American species instead such as the summer-flowering, green-budded white Hydrangea arborescens ‘Annabelle’.
If you want a hydrangea for a shady position opt for the autumn-flowering Hydrangea paniculata instead.
Where to plant
The one common thing about all hydrangeas is a need for a sheltered position out of the wind. Leaves scorch horribly in windy gardens and plants fail to do well. They also prefer some shade - even the drought-tolerant American species. The climbers are very good in shade. Hydrangeas do well under trees - particularly H. paniculata.
Position your hydrangea so that it avoids the midday sun on its roots. Some gardeners place hydrangeas on the sunless side of a low garden wall to keep the roots cool. Generally light shade is best for most, or afternoon and evening sun.
Hydrangea arborescens will take whatever the weather throws at it. However on damp soils, or in wet summers, it can become invasive and land grab from other plants.
When to plant
Plant hydrangea in the spring.
How to plant
Dig a large hole and add plenty of organic material such as garden compost, or add John Innes no 3 because this compost contains loam. Both will help to retain moisture in the ground.
Mulch with bark to keep the soil moister. Water well in the first growing season and be prepared to water in every dry summer. The best technique is to gently tip a bucket of water over the roots about once a week.
When it blooms
Hydrangea blooms at different times depending on variety, but it is usually in summer.
In spring, prune Hydrangea macrophylla back to the lowest emerging buds if you have die back following a hard winter. Do not prune unless you need to. And never prune hard - you will cut away all the flowers. Other types of hydrangeas are more forgiving.
Always avoid frost pockets, because early and late frosts are resented by hydrangeas and this is why they do so well in a maritime climate that avoids extremes.
If you do need to prune a mature specimen of Hydrangea macrophylla, remove one or two stems at the base, but leave several intact.
Hydrangea arborescens can tolerate drought, heat and extreme cold. In very cold winters it will die down completely and reshoot in spring, to flower in July. In milder winters it will grow away and flower four weeks earlier.
When to take cuttings
Start new cuttings early in the summer to give them the best chance for surviving the winter.
Hydrangea flowers dry well if picked at their peak, or they can be picked as they fade as well.
Cut back to shooting buds in spring and then use a slow-release fertiliser (like 6 x) or sprinkle blood, fish and bone.
Hydrangea colour varies depending on the soil. Add sequestered iron if you want blue flowers.
Five of the best Hydrangea macrophylla
A black-stemmed blue hydrangea with a lacecap arrangement of flowers.
A striking deep-pink to wine-red lacecap. The name means Red Start.
‘Endless Summer Pink’
This is an easy pink mophead capable of flowerting from basal shoots, so very good in a cooler garden.
‘Generale Vicomtesse de Vibraye’ AGM
A good rose pink mophead, but blue on acid soil.
A purplish-blue to dark pink mophead – again depending on soil.
Three of the best Hydrangea arborescens
A lovely cream-white form which produces flowers from green buds. Cool and fresh.
A floppy stemmed, cream starry double that’s fantastic in a container, but too brittle for most places in the garden.
The only pink form of Hydrangea arborescens, but already widely available. It should produce more pink forms.