Hydrangeas come in so many different varieties, with the most popular being mopheads.
These hydrangeas boast full, round heads brimming with large petals, while lacecaps feature tiny flowers at the heart of the bloom, surrounded by a halo of larger petals.
Green-fingered guru Jessica Walliser, an award-winning horticulturist and author of seven gardening books, took to her garden blog Savvy Gardening to share that when it comes to these hydrangea varieties, you should “never” prune them in autumn.
She cautioned: “Whether you are growing gorgeous panicle hydrangeas like these or classic mophead hydrangeas, pruning should never be done in autumn.”
Jessica warned that an ill-timed trim could spell disaster for the flowers, as autumn pruning might “no blooms next year”.
While mophead hydrangeas’ spent blooms can be snipped off post-flowering in milder climes, it’s wiser to let them linger through the winter, says the Royal Horticultural Society (RHS).
The gardening gurus advise that the “correct time” for most pruning be carried out in late winter or early spring. However, climbing hydrangeas are pruned after flowering in summer.
This practice offers a shield of frost protection for the “tender growth” buds nestled beneath.
They recommended: “Remove the dead flower heads in early spring, cutting back the stem to the first strong, healthy pair of buds down from the faded bloom.”
For the more robust lacecaps, RHS experts recommend trimming the old flower heads back to the second pair of leaves below the head right after they’ve bloomed, preventing seed formation which can drain the plant’s vigour.
For those who have established hydrangeas in their garden, it’s best to slice off a couple of the oldest stems right at the base to spur the growth of fresh ones. This little trick is meant to “boost flower productivity”.
If your hydrangea has turned into a bit of a wild beast, don’t fret as a complete overhaul can be achieved by chopping all its stems down to their base.
However, as the experts point out: “This will remove all the flowers for that summer. The stems won’t bloom until the following year.”
In case there’s any unfortunate frost damage when spring rolls around, the pros recommend pruning the impacted shoots just above the first pair of healthy buds on sturdy wood.
Weeding out feeble, leggy stems is also key to maintaining a robust hydrangea, they emphasised.