Cutting hydrangeas: how to make them bloom beautifully

When pruning hydrangeas, many amateur gardeners are unsure because different pruning rules apply to different types of hydrangeas. Here we explain what you need to pay attention to and how to make the bushes bloom splendidly.

You can’t do much wrong when pruning hydrangeas – provided you know what type of hydrangea it is. In our video, our garden expert Dieke van Dieken shows you which species should be cut and how
Credits: MSG/CreativeUnit/Camera+Editing: Fabian Heckle

Hydrangeas of pruning group 1
When to cut hydrangeas?
Special case of hydrangea ‘Endless Summer
Hydrangeas of cutting group 2

Hydrangeas of cutting group 1
When should you cut hydrangeas?
Special case hydrangea ‘Endless Summer
Hydrangeas of pruning group 2

Hydrangeas are easy to care for and bloom for a very long time – in addition, their inflorescences are still attractive even when withered. No wonder that hydrangeas are among the most popular garden plants and can be found in almost every garden. When it comes to pruning hydrangeas, however, many amateur gardeners are unsure – and for good reason, because hydrangeas are pruned at different rates depending on which species they belong to. If you prune incorrectly, the bloom may fail the following year. One therefore divides the plants into two pruning groups.

Pruning date for all hydrangeas is the end of February
For farmers hydrangeas, only remove old flowers and frostbitten shoots
Always cut just above the first pair of green buds
in the case of panicle and ball hydrangeas, trim old flower shoots to one or two pairs of buds
if the bushes are very dense, cut out individual old shoots completely

Cut tips on the ears

In this episode of our podcast "Grunstadtmenschen" Karina Nennstiel and Folkert Siemens tell you everything you need to know about pruning ornamental shrubs – from hydrangeas to clematis and from the various summer bloomers to spring bloomers. Have a listen!

Hydrangeas of cutting group 1

The plants of cut group 1 include all varieties of the farmer hydrangea (Hydrangea macrophylla) and the plate hydrangea (Hydrangea serrata) as well as the giant leaf hydrangea (Hydrangea aspera ‘Macrophylla’), the velvet hydrangea (Hydrangea sargentiana), the oak leaf hydrangea (Hydrangea quercifolia) and the climbing hydrangea (Hydrangea petiolaris). All of these hydrangea species have one thing in common: they lay down new shoots for the next year, including terminal flower buds, the previous year. If you carefully open a bud of the farmer’s hydrangea in autumn, you can already see the new inflorescence and leaves inside it.

Peasant hydrangea (Hydrangea macrophylla)

The farmer’s hydrangea (Hydrangea macrophylla) belongs to pruning group 1

As a result, hydrangeas in pruning group 1 should be pruned back only lightly to protect new shoots. As a rule, one removes the old inflorescence just above the first intact pair of buds and, if necessary, thins out the entire plant a bit more by cutting off the oldest shoots at ground level. You can of course prune the above hydrangeas more in spring, but then you will have to do without the beautiful flowers for a year.

For hydrangeas in pruning group 1, only the old inflorescences are removed in spring

When to prune hydrangeas?

The best time to prune hydrangeas of pruning group 1 is early spring. Most hydrangea species of this cutting group are somewhat sensitive to frost. Therefore, with the old inflorescences also remove all the shoot tips that froze in the winter. Again, you should cut off all shoots at the height of the first healthy buds. Tip: If you are not sure whether a shoot of your hydrangea is frostbitten or still alive, you should simply scrape off a little of the bark with your thumbnail. If bright green tissue appears underneath, then the shoot is still intact. The bark tissue of dead shoots is usually already somewhat dried and has a yellow-green hue.

Special case hydrangea ‘Endless Summer

The hydrangea ‘Endless Summer’ is botanically very close to the classic farmer’s hydrangea, but it has a special characteristic: Heavily cut back flower branches from the previous year sprout again and, in contrast to the normal farmer’s hydrangea, still bear flowers in the same year. That’s why you can cut back the blue ‘Endless Summer’ and the white ‘The Bride’, which comes from the same breeding line, as much as you want in the spring. Basically, however, you should also remove only the faded inflorescences with these varieties, otherwise the new flowering starts relatively late.

Tip: If you remove the first flush of flowers in the summer immediately after the hydrangea has faded, the plants will form new flowers on the shoots. Therefore it is worthwhile, as with the more frequently blooming roses, to reach in the summer again and again for the garden shears.

The hydrangea ‘Endless Summer can be cut back as much as desired in spring

Hydrangeas of the cutting group 2

Cut group 2 includes all hydrangeas that form their flower buds only in the year of flowering on the new shoots. This includes only two species: the snowball hydrangea (Hydrangea arborescens) and the panicle hydrangea (Hydrangea paniculata), each including all cultivars. Hydrangeas in pruning group 2 are pruned like classic summer bloomers: in late fall or spring, simply trim all shoots that emerged last season to short stubs, each with a pair of eyes. In the coming season, the remaining eyes sprout vigorously and long new shoots with large terminal flowers appear.

For snowball hydrangea and panicle hydrangea, cut back all shoots to short stubs in early spring or as early as late fall

With this pruning technique, the number of shoots doubles year after year, as two new shoots are produced from each old one. If the crowns become too dense over time, you should therefore prune weaker or awkwardly placed shoots or individual "twig brooms" remove completely.

Important: Do not cut back these plants too late, because otherwise the flowering will also start relatively late. You should have pruned the woody plants by the end of February. In protected locations, it is also possible to prune much earlier – for example, already in late autumn – because the plants are more frost-hardy than the hydrangeas of pruning group 1.

Officially, hydrangeas are classified as slightly toxic and particularly sensitive people may experience contact allergies in the form of skin irritations when caring for the plant. If you know that your skin is sensitive to contact with plants, it’s better to wear gloves when caring for hydrangeas.

Become a hydrangea pro with our podcast!

In this episode of the podcast "Grunstadtmenschen", Nicole Edler and Folkert Siemens tell you what else you need to keep in mind when caring for hydrangeas, in addition to pruning, so that the blooms turn out particularly lush. It is worth listening!