The Hydrangeas are a type of flower that differ from normal mop head varieties. The H. Paniculata and the H. Arborescens types bloom on new stems made in this current season, so they need to be pruned differently than typical ones which produce flowers on growth generated over the past year.
To ensure there is good production of these plants with their large blooms, you should perform your pruning in February or March – either at ground level or around one main trunk where it’s been allowed to grow taller.
Pruning should be done annually to maintain a healthy, attractive plant. Without this annual pruning, the shrub will turn into an unkempt mess of tangled branches and small flowers that get smaller each year.
When & Home to Prune
Hydrangeas can either be grown as an arching cascade starting from near to ground level (12 inches) or you can train with a framework that starts its new annual growth at a higher level (no more than 24 inches). When trying to grow it as small weeping tree, there are many difficulties.
Hydrangea’s top growth is considerable, and the basic root system will not support it if allowed to develop into a small tree. For these two reasons pruning regime should always remain consistent so plant does not wear out too quickly while looking good for your desired form of flower shape.
The best time to prune a Hydrangea is in late winter, before the flowers come out. One month prior to your normal spring starting date will give you just enough time for any buds that are put on show and have yet to bloom their full potential. However, unless an emergency, do not wait until later in the year as this can result in small flowers due to nutrient deficiency from new shoots which have not had sufficient growth or nutrient replenishment.
You will need strong secateurs or a sharp lopper. Pruning with blunt implements will result in crushed stems, allowing dieback and fungal disease.
A good way to trim is by cutting back previous years’ flowering branches near the old framework – this creates ‘stumps’ from which new shoots grow.
The cuts should be around 4-5 inches (10 – 12 cm) from the base of these cuttings – you are creating ‘stubs’ that have buds on them which will grow rapidly and form an arch over the course of the next year.
Hydrangeas are beautiful, stunning flowers that can grow up to 1.8 metres tall and beyond by mid -summer with the right care. By following these tips you’ll be able to keep your Hydrangea in good shape all year long too.