Summer flowering hydrangeas are the synonymous with November. Their showy heads of white, blue or pink flowers are a delightful addition to any garden, and they grow well in shady gardens, making them really useful for tricky, dark corners that need a pop of colour. Hydrangeas are also excellent as potted plants, provided you don’t let them dry out.
There are many species, but the most common is Hydrangea macrophylla. This is a traditional style Hydrangea but they also come in Mophead or Lacecap varieties. ‘Endless Summer’ are repeat flowering types worth including too. They produce abundant blooms on both old and new wood all summer long. Other species include Hydrangea paniculata, the most common cultivar of which is 'Kyushu' is part of a hardy new range of shrubs featuring an improved form and impressive floral display. Sometimes we also stock oak leaf hydrangeas in our rare and unusual plants section. They have white panicle blooms and oak shaped large leaves that turn a rich red in autumn before falling.
Flower colour is affected by pH; an alkaline soil will turn the flowers pink and flowers turn blue if the soil is acidic. White is unaffected by the pH of the soil. If you want to manipulate flower colour you should apply hydrangea blueing tonic or lime (for pink flowers) in late winter.
If you have plenty of blooms in the garden and want to bring some inside, make sure you cut them first thing in the morning before the heat spoils them, and plunge them straight into cold water to keep them from wilting. When you’re back inside, cover them in the sink with water as you’re arranging them, and recut their stems on an angle as you place them into a vase. Picking them as the colour is only half way through its development will mean your blooms have the longest vase life.