Pruning Hydrangeas is important to keep them healthy and growing while improving their flower production. Learn how to prune them correctly.
Pruning Hydrangeas is not a difficult task; you need to do it at the right time of year. You will also need to determine if your shrub blooms on old or new wood. Follow these tips to ensure you’re pruning hydrangeas in the right manner to keep them blooming abundantly.
To determine if your hydrangea blooms on old or new wood, keep a tab on its flowers.
Shrubs that produce blooms on old wood, generally begin blooming in early summer and cease blooming by midsummer. Shrubs that produce blooms on new wood generally start blooming later than old-growth bloomers because they must set their buds the same year they bloom. New-wood bloomers will begin to flower in midsummer and continue until frost.
Old Wood Pruning
Hydrangeas that bloom on old wood will set their buds for next year, not long after they finish blooming at the current year. Prune these shrubs as soon as the blooms begin to fade in late summer to prevent cutting off next year’s blooms. The sooner you prune an old-wood hydrangea, the better it will be as it’ll give the shrub a time to recover before winter and will produce larger blooms next year.
Prune off fading blooms just below the flower head. Remove any diseased or straggly branches by cutting them off at ground level. Rejuvenate an old shrub by cutting the oldest branches off at the soil level. An old, woody hydrangea, will produce small blooms. Pruning away a few of the oldest branches will energize the plant, enabling it to produce more and bigger blooms.
New Wood Pruning
Hydrangeas that bloom on new wood takes all the guess-work out of pruning. These shrubs are cut all the way back to the soil level in late winter or early spring. This is called ‘hard pruning’ and enables the shrub to remain healthy, producing more and larger blooms each year.
If your new-wood shrub is old and large, it may subject to ‘flopping’ each year if given a hard pruning. Flopping occurs when the new, tender branches become wet from rain or watering and are unable to remain upright under the weight of the water and blooms. To prevent flopping, space your plants properly and prune new-wood hydrangeas to 18 inches high in late winter or early spring. This will form a network of old, woody branches that will support the new growth, preventing flopping.