Mophead hydrangeas and lacecap hydrangeas, commonly known as bigleaf hydrangeas (Hydrangea macrophylla), are pruned using the same technique.
With its broad, roundish heads of huge petals in colours of blue, pink, green, and white, mophead hydrangeas are a popular choice for gardens. They are therefore a popular shrub option for cottage garden ideas and are also effective shade-giving bushes.
Small blooms in the center of the bloom and a border of bigger petals on the outside help identify lacecap hydrangeas.
The experts at Thompson & Morgan suggest that in order to winterize hydrangeas, “it’s better to leave the faded blooms in place over the winter to safeguard vulnerable new buds from frost damage.”
Early in the spring, while pruning lacecaps and mophead hydrangeas:
- To promote new growth that will produce better blooms, remove one or two of the plant’s oldest, weakest stems at the base.
- Just above a pair of buds, carefully remove any old flowerheads using secateurs.
- Don’t remove any of the blossom buds, please.
- Cut the stems down to the plant’s root system if the bigleaf hydrangea shrub has been neglected and has a lot of overlapping, tangled branches. The hydrangea won’t blossom until the next year, though.
What happens if you completely prune hydrangeas?
These hydrangeas are simple to manage because they bloom each year no matter how they are taken care of or treated. They can be cut down to the ground in the fall and will reappear the next spring with an abundance of blossoms. However, over time, this severe trimming might make the plant gradually weaker.
If chopped, will a hydrangea grow back?
If you have hydrangeas like panicle and smooth hydrangeas, which set bloom buds on current season wood, you can be more liberal about pruning. Winter or fall are the optimum times to prune them. Even if you trim canes to the ground when the bushes are dormant, they will grow back and flower in the spring. However, cutting stems all the way to the ground over time weakens them, so you might need to stake the plants to keep them standing. This severe trimming could eventually make the plant grow back weaker.
When shouldn’t hydrangeas be pruned back?
Depending on which group the plant belongs to, the timing and extent of pruning are determined:
Advice on Pruning for Group 1:
- As the days get shorter and the weather gets colder in the late summer and fall, buds for the following year’s blooms start to form.
- Typically, removing dead, diseased, or damaged branches is all that is required to preserve shape, size, and a healthy plant. Otherwise, gentle pruning ought to be practiced.
- In the summer, trimming should begin as soon as flowering ends, but no later than August 1. Pruning should not be done in the fall, winter, or spring because you risk removing fresh buds.
- Tip-pruning the branches in the spring as the leaves begin to appear can promote more numerous, smaller flower heads as opposed to fewer, larger flower heads.
Advice on Pruning for Group 2:
- On the growth of the current year, flower buds form.
- Early in the spring, as the leaves are starting to emerge, prune.
- Just above a node, prune branches back by half to a third.
- After that, prune any fragile or spindly branches.
- Minimal trimming encourages huge, strong bushes with many of tiny flower heads in H. arborescens. Hard pruning between 12 and 18 inches from the ground, or even all the way down, will result in fewer but larger flower heads that may flop if unsupported.
- For H. paniculata, remove the surrounding smaller wood while leaving the larger stems in order to establish a sturdy foundation.
Pruning may be connected to flower head size. Shoots will grow more vigorously and flower heads will be bigger and fewer with more rigorous trimming. Smaller but more numerous flower heads may result from less aggressive or tip pruning.
Consideration of hydrangeas’ mature size is the best piece of advise. Place them in a location where they won’t outgrow and won’t need a lot of pruning to keep them in check. Hydrangeas don’t need to be pruned precisely or often; as long as dead wood is removed, they will remain healthy and continue to develop and bloom.
Cut back these shrubs in late winter before new growth begins
Shrubs that flower on young wood typically start blooming later than old-growth bloomers, beginning in June and continuing until the first frost, because they need to grow and set buds the same year that they bloom. As long as you avoid trimming when the flower buds are opening, these shrubs are understanding if it is not done at a specific period.
1. Trim the flowers all the way back for larger blooms.
These bushes can be completely removed from the ground in late winter or the beginning of spring. If cut severely like this every year, smooth hydrangeas will produce much larger flowers, but many gardeners prefer smaller blooms on stronger stems.
2. Maintain an old growth foundation to lessen flopping
Especially after watering from above or after a heavy storm, the branches of some hydrangeas frequently topple over from the weight of their blooms. Cutting the stems to a height of 18 to 24 inches will help to reduce this flopping by creating a strong framework for fresh growth.
Janet Carson is the University of Arkansas Cooperative Extension Service’s horticulture specialist.
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