Hydrangeas are large, hardy plants that can grow up to 10 feet in a single season. The bushes bear large bursts of pink, blue, and white flowers, and will bloom throughout the season.
Although there are two distinct types of hydrangeas, they all begin to bloom in spring when the air warms, or in midsummer.
Hydrangeas of all sorts bloom throughout the growing season. Individual blooms last for weeks, while the plants continue to put out new blooms to replace the old. Most gardeners prune away old, spent blooms to encourage the plants to put out new flowers.
Pruning should not take place until after a hydrangea is finished blooming. In August or September, before the plants set their buds for the next year, gardeners should cut away any old or diseased wood and spent flowers or foliage. Pruning at the wrong time, or pruning away future flower blooms, will keep the hydrangea from blooming again the next spring.