Of the approximately 70 species of hydrangeas that exist worldwide, only a few have any significance in our climate zone. However, the breeders were even busier because there is an almost unmanageable number of varieties and breeds. When it comes to hydrangeas, it is very important to know the exact type and variety, as the specific cutting measures depend on this.
How do I cut a garden hydrangea correctly?
On garden hydrangeas, only the old inflorescences should be removed in spring. Rejuvenation or thinning cuts can cut a third of the oldest shoots above the ground. Perennially flowering varieties require regular pruning of dead areas to encourage further flowering.
Do not cut back garden hydrangeas too much
Hortensias are usually divided into two pruning groups by experts: The first group blooms on the previous year's wood and should under no circumstances be cut back heavily in the spring. The second group blooms on this year's wood and can easily be cut back radically in the spring. Garden hydrangeas (Hydrangea macrophylla) belong to the first group, which is why only the old inflorescences need to be removed in spring. However, there are new Marcophylla varieties that bloom on both old and new wood. These can also be cut back a little more if you are aiming for a more compact growth.
New long-flowering garden hydrangea varieties
So far, garden hydrangeas have only bloomed on old, last year's wood. With the varieties “Endless Summer” and the “Forever & Ever” series, there are now hydrangeas that also produce flowers on fresh, annual shoots. New buds form approximately every six weeks and open the same summer. The advantage of this new variety is its joy of flowering: even if flower buds freeze in spring, new buds are immediately formed on the young shoots.
| Variety | Flower color | Flowering time | Growth height | Growth width | Winter hardiness |
|---|---|---|---|---|---|
| Endless Summer | blue to pink (depending on pH value) | July to October | 150cm | 180 cm | good |
| Forever & Ever “Pink” | blue to pink (depending on pH value) | July to October | 90 cm | 120cm | good |
| Forever & Ever “Blue” | blue to pink (depending on pH value) | July to October | 90 cm | 120cm | good |
| Forever & Ever “Red” | intense pink red | July to October | 90 cm | 120cm | good |
| Forever & Ever “Peppermint” | white-pink | July to October | 90 cm | 120cm | good |
| Endless Summer “Twist & Shout” | pink | July to October | 150cm | 180 cm | good |
Rejuvenation or thinning cut
In the first few years, garden hydrangeas do not require any pruning at all. It's best to leave them completely alone at first so that they can build up into even bushes. They can be photographed regularly later. In spring, cut off a third of the oldest shoots just above the ground. In this way, the growth of new shoots is stimulated from below. This is how you avoid the bushes becoming senescent.
Pruning measures for long-flowering garden hydrangeas
With the new, long-flowering Marcophylla varieties, you should regularly cut out everything that has bloomed in order to stimulate further flowering. Only the flowers that appear later are left on the plant as autumn and winter decorations and only cut off in the following late winter / spring.
Tips & Tricks
If your garden hydrangea doesn't really want to bloom or doesn't form any buds, the cause is usually incorrect pruning, for example because dead flower stems were cut too low in the previous autumn or because the plant was pruned in spring. Do not cut back garden hydrangeas, just cut off the old inflorescences.