In general hydrangea plants do not require annual trimming, but occasionally pruning hydrangeas can improve plant performance in many ways. Hydrangea pruning can increase crop yield and the quality of the flowers. Hortensia trimming is also a way of shaping the plant, controlling and directing growth, and it helps with diseased, damaged, and unwanted tissue. Cutting back hydrangeas can also produce bigger flowers. When you prune hydrangeas you are also removing deadwood and dead blooms, and this can improve plant health. Other methods of pruning are used for nursery specimens and for transplanting. Note that pruning is not the same as removing dead blooms.
Pruning Differs by Type of Hydrangea
Depending on what type of hydrangeas you are growing in your garden, how and when to prune a hydrangea plant will differ. Mophead hydrangeas do not need to be pruned back unless the plants are very old. Removing dead stems and dying blooms can be done at any time on all types of hydrangeas and this is good for the health of the plant. It is best to cut back and trim hydrangeas after the flowers begin to fade in late summer. Pruning hydrangeas also differs if the plants you are growing bloom on new wood or bloom on old wood.
Pruning hydrangeas removes deadwood and old blooms and helps produce pretty shapes, beautiful new and large flowering blooms.
What is Hydrangea Pruning?
Pruning is a horticultural method, which involves the selective removal of some of the parts of a plant, such as branches, buds, roots, or flower blooms. Specialized pruning can be applied to hydrangea plants for different reasons. Gardeners use a number of garden tools to prune plants. Pruning hydrangeas involves removing a portion of growing stem down to a set of desirable buds or side-branching stems. Pruning stimulates growth of flowers and branches, and encourages growth of the stems in a desirable direction. Cutting back or thinning involves the removal of an entire shoot, limb, or branch at its point of origin. Thinning is done to revitalize the hydrangea plant by removing over-mature, weak, problematic, and excessive growths. Trimming the plant also encourages the formation of new growth that will more readily bear flowers. The pruning regime in flower farms is deliberately planned as the flower productivity of each hydrangea plant is an important factor in floriculture.
Reasons for Pruning Hydrangeas
- Light Deficiency
- Pest and Disease Damage
- Root Structure Damage
- Crown and Canopy Thinning
- Crown Reduction and Lifting
- Directional or Formative Pruning
- Vista Pruning
Pruning Old Wood vs New Wood
If you want your hydrangeas to bloom as well as they possibly can, it is important to find out what kind of hydrangea (species) you are growing. If the blooms on your hydrangeas are pink, purple, or blue, you definitely have a mophead or lacecap (macrophylla) hydrangea. If the blooms are white, they could be any type hydrangea.
Produce Beautiful Blooms
Pruning hydrangeas can help them retain a pretty shape and produce beautiful blooms year after year. Not all hydrangeas are pruned at the same time, so it’s important to know what variety you have before you go outside with those pruning shears. if you prune your hydrangea at the wrong time of year, you could cut into next season’s blooms. Old Wood are stems that have been on the hydrangea plant since the summer before the current season. New Wood are stems that developed on the hydrangea plant during the current growing season.
Old Wood Blooming Hydrangeas
To determine if your hydrangea blooms on old wood, think about when it flowers. Shrubs with this characteristic generally begin blooming in early summer and peter out by midsummer, though sporadic blooms may appear afterward. These shrubs form next year’s flower buds in late summer or early fall as the days get shorter and temperatures cool off. To reduce the risk of removing these buds, prune just as the flowers begin to fade. Often, the earlier you get it done after bloom, the quicker the shrub can recover, producing more and larger blooms next season.
Get Bigger Hydrangea Flowers
To get bigger flowers, cut them all the way back. In late winter or early spring, these shrubs can be cut all the way back to the ground. Smooth hydrangeas will produce much larger blooms if pruned hard like this each year, but many gardeners opt for smaller blooms on sturdier stems. Removing old blooms on a plant is called deadheading.
How to Prune Hydrangeas
How to prune hydrangeas.
Mophead and Lacecap Hydrangeas
Prune these macrophylla mophead and lacecap hydrangeas right before the end of the summer. Prune these types of hydrangeas before they have set their bloom buds for the next year. This group of hydrangeas produce flower buds on hydrangea stems around the late summer and early fall. If those stems are trimmed (pruned) in the fall, winter, or spring, the bloom buds will be removed, and there may be little or no bloom the following summer.
Paniculata Hydrangeas (PeeGees)
Paniculata hydrangeas (PeeGee/Limelight types) can be pruned in the fall, winter, or spring. However, it is not necessary to prune them every year. It is suggested that one trim out crossing branches and those that do not contribute to an attractive form whenever necessary. Paniculata hydrangeas are the only hydrangeas that can be pruned into a tree-form. If a panicultata that is trained into a tree-form is cut or broken off close to the ground, it will grow back as a shrub unless the training and pruning is started again from the new shoots.
Arborescens (Annabelle) types of hydrangeas bloom on new wood (new stems). It is a joy to grow these type hydrangeas because they are determined to bloom every single year, no matter how they are treated. The only time they cannot be pruned is in the spring when they are preparing to bloom.
When to Prune Hydrangeas
Most pruning is carried out in late winter or early spring. However, the climbing hydrangea is pruned after flowering in summer.