Hydrangeas are one of my favorite shrubs and I never get tired of seeing their stunning blooms in summer and fall. They create a wonderful visual impact and I wouldn’t be without them in my garden. My favorites are “Strawberry Sundae” for its frothy cream and pink flowers and the “Annabelle” hydrangea for its classic white globe-shaped flowers.
These easy-to-grow shrubs are ideal for novice gardeners, but are equally popular with gardening enthusiasts. With proper care, hydrangeas will create a spectacular display in your garden.
However, hydrangeas can become overgrown and unruly if they are not pruned. Proper pruning will ensure they remain in good shape and healthy, promoting new growth and buoyant blooms.
Therefore, to get the most out of your hydrangeas, it is important to know what pruning mistakes to avoid and how to prune them correctly. Then you will feel confident that your hydrangeas will be healthy and create beautiful blooms throughout their blooming season.
1. Prune your hydrangeas at the wrong time
It may be tempting to prune hydrangeas once they stop blooming in the fall, but this is not the right time. While you may want to cut the hydrangea once the flowers turn brown, pruning should be left for later.
The perfect time to prune most hydrangeas is in late winter and early spring, making it a good weekend job during the month of March. Pruning after winter frosts also helps protect the plant from winter damage.
However, climbing hydrangeas should be left until early summer. This is because climbing hydrangea flowers are produced on old wood. Pruning too early in spring risks removing new growth before it blooms.
By pruning your hydrangeas at the right time, you will prepare your plant for its best growing season.
Don’t confuse pruning with pruning. Pruning and pruning are two very different things. Hydrangeas can be cut at any time to tidy up the plant. It simply involves cutting off the flower head just below the stem, leaving all the leaves intact. Pruning should be done at a specific time, depending on your type of hydrangea and helps shape the plant.
Advice:
Rather than cutting back my hydrangeas, I prefer to keep them intact as the flower heads look stunning and provide winter interest in my garden. And while I enjoy admiring them outside, I can never help but cut a few stems to display indoors.
2. Use blunt tools
We all know what it’s like to use dull knives in the kitchen. You do not get a clean cut and it is impossible to cut hard foods. It’s a similar story in the garden. Tools that have been used but not maintained are not up to par and do not work as well as they should.
Pruning shears Those that have been used excessively, have not been cleaned after use, or have been left exposed to rain to rust are particularly problematic. If you use dirty or blunt tools to prune your hydrangeas, you are putting their health at risk.
A dull blade will crush and tear plant tissues, causing a jagged cut that will take longer to heal. Like an open wound, it leaves the plant more susceptible to diseases and pests, which can also be transmitted if you don’t clean your shears. You may also have to apply more pressure to make the cut, crushing the stem instead of making a clean, precise cut.
So, for the benefit of your hydrangeas, get the best out of your pruning shears Always find time to clean and sharpen them regularly.
3. Pruning at the wrong angle
Be sure to cut the stems at an angle rather than straight across. A flat cut will leave the plant more vulnerable to fungal infections. When it rains, water will pool in the wound instead of running off.
Cut at a 45° angle in the same direction as the bud, placing the pruning shears ¼ inch above the bud.
Did you know?
It is also common to cut fresh flowers at 45°, as the larger surface area allows more water to be absorbed. It is one of the tips that we mention in How to keep your cut tulips fresher for longer.
4. Being overzealous
If you’re like me, I have to control myself when I have a cutting tool in my hand. I get overzealous and tend to opt for a full cut rather than a neat cut. I must be especially careful when pruning my hydrangeas, as they do not require much pruning to bloom well each year.
If you remove more than a third of the plant, you risk stressing it and not performing as expected, and you could limit new flowers from hydrangeas that bloom on old wood.
With this in mind, I follow the rule of one third, which is often recommended when pruning hydrangeas. It is based on not removing more than a third of the bush at a time. This could include cutting back one-third of the oldest stems from the base of the plant to encourage new shoots or one-third of the length of a stem.
If you remove more than a third of the plant, you risk stressing it and not performing as expected, and you could limit new flowers from hydrangeas that bloom on old wood. The idea is to be careful with pruning to encourage new shoots.
5. Hydrangeas are not all the same
Pruning hydrangeas can seem confusing, as there is no single approach that covers all varieties. Therefore, you will need to determine which variety you are growing to ensure the best flowers and avoid pruning potential flowers.
While some hydrangeas bloom on new wood, others bloom on old wood. Broadleaf, oakleaf, and mountain hydrangeas bloom on old wood, while panicle and smooth hydrangeas bloom on new wood. Although climbing hydrangeas flourish on old wood, they need to be pruned differently than any other.
Hydrangeas blooming on old wood
Broadleaf hydrangeas (Hydrangea macrophylla)
Flower head: Large mophead or lacecap heads, white, pink, blue, purple or red.
Pruning: Minimal pruning needed, remove dead wood before spring growth begins
Oakleaf hydrangeas (Hydrangea quercifolia)
Flower head: oak-shaped leaves, white to pink and purple.
Pruning: Trim winter-damaged stems in early spring.
Mountain hydrangeas (Hydrangea serrata)
Flower head: Mophead or lacecap flower heads
Climbing hydrangeas (Hydrangea anomala)
Flower head: lace heads, white.
Pruning: After flowering in summer.
Hydrangeas blooming on new wood
Panicle hydrangeas (Hyrangea paniculata)
Flower head: cone-shaped, white flower heads.
Pruning: Prune from late winter to early spring.
Smooth hydrangeas (Hydrangea arborescens)
Flower head: Mophead or lace flower heads, white to pink
Pruning: Pruning in autumn or early spring.
- Here are 7 plants to prune in March according to an expert
- Discover how to prepare hydrangeas for winter
- And 5 mistakes to avoid when growing hydrangeas
