Proper hydrangea autumn care is essential for maintaining the health of this popular shrub. If you want to see plenty of big, colourful blooms in the summer, then learning how to care for hydrangeas in autumn is a critical step. If you prune them incorrectly or neglect to properly protect them from the elements, your hydrangea-growing efforts could be a failure.
According to garden experts at Gardening Know How, to ensure you have a “bounty of blooms” next summer, there are “two vital tasks to prioritise in autumn” – mulching and pruning. They claimed that if you get these two tasks right, gardens will be “bursting with blooms that stop their neighbours in their tracks”.
1. Mulch your hydrangeas
As hydrangeas don’t do well when their roots freeze, mulching them before winter “really helps”.
They pointed out that a good layer of mulch keeps the ground from getting either too hot or too cold when the weather shifts, which is a common cause of stress in plants.
Apply a two to three-inch layer of bark chips or other mulch around the base of hydrangea plants. Avoid placing bark against the trunk, which can make plants more susceptible to pests and diseases.
Make a doughnut shape of mulch around your hydrangea. You can also use shredded fall leaves for this job.
2. Lightly prune your hydrangeas
When it comes to pruning hydrangeas in autumn, the goal isn’t a big makeover, just a little cleanup. It’s best to prune old wood blooming varieties like bigleaf and oakleaf hydrangeas as soon as flowers fade.
When trimming hydrangeas, remove any dead or crossing branches, and if a stem has grown too long, trim it just above a healthy bud. But that’s where you should stop.
If you go further, you might regret it in the summer when the flowers fail to appear. Incorrect pruning is a leading cause of hydrangeas not blooming.
For panicle hydrangeas and smooth hydrangeas, which flower on new growth, avoid pruning in autumn and hold off on any cuts until spring.