When should you cut hydrangeas? After flowering? And how much?

Hydrangeas are one of the most popular garden plants and are at home in almost every garden. But many hobby gardeners are uncertain when it comes to cutting. Different rules apply here. In the plant guide you can find out which rules apply to which species and what special attention must be paid to.

Importance of the right cut

While general cutting recommendations apply to many plants, the hydrangea is sensitive to improper pruning. The garden plants with the botanical name "Hydrangea" are divided into two groups with regard to cutting. The most important thing here is when and how thick they should be cut. The right time in combination with the amount of pruning decides whether the hydrangea is in the will bloom in full splendor in the coming gardening season or you will completely refrain from blooming in that year have to.

grouping

Cutting group 1

This grouping of hydrangea species and varieties are specimens that will be preparing for the next flowering season as early as autumn. Here they develop new shoots and terminal flower buds. In autumn, if you look closely, you can see them. If you carefully open the still small buds, the new inflorescences are visible for the following year. If you prune the hydrangeas too far back in autumn or spring, you would also remove numerous shoots and flower buds. As a result, the hydrangea will then bloom significantly less and, in the worst case, the flowers will fail completely.

Hydrangea species / varieties belonging to this group:

• All farmer's hydrangea varieties (Hydrangea macrophylla)
• Oak leaf hydrangea (Hydrangea quercifolia)
• Climbing hydrangea (Hydrangea petiolaris)
• Giant-leaf hydrangea (Hydrangea aspera "Macrophylla")
• Velvet hydrangea (Hydrangea sargentiana)
• Plate hydrangea (Hydrangea serrata)

Cut time

The best time to cut a hydrangea belonging to this grouping is this early spring. In autumn, because of the cold snap that is possible at any time, no major pruning should be done. This is based on the mostly available Sensitivity to frost, which the hydrangea from this grouping predominantly has. The risk is too great that she will suffer damage from frostbite, as larger cuts favor this.

In addition, each pruning weakens a plant, which makes it much more difficult to get through the winter without frost damage. In particular, the buds that have already formed for the following year could freeze to death and thus immensely impair the bloom. This is why the following applies to the hydrangeas of this group: it is best to only cut them in spring, although old, withered flowers can be safely removed in autumn.

This is how the cut works

If the hydrangea has survived the winter well, pruning should be avoided in principle. Only if it shows severe frostbite or illnesses have weakened it enormously, a large-scale pruning or radical pruning is recommended. The flowering will not happen that year, but ideally you will save her life. In the following year you can look forward to a generous display of flowers. Here you can shorten the hydrangea up to a maximum of 20 cm above the ground. It must at least one pair of flowers remain.

Otherwise, remove maximally withered flowers in autumn. In early spring, the cut should be made as follows:

• Remove the old inflorescence if it has not already been done in autumn (usually located above the new buds)
• Cut off frozen parts of the plant into the healthy / green area - in the case of severe frostbite, cut off near the ground
• Clearance cut: old shoots are mainly cut from the inside of the plant to ground level
• Thin shoots that do not have buds should be shortened by a few centimeters so that they gain strength

tip: You can test whether a shoot has frozen by lightly scratching or scratching the bark. If green tissue appears, there is no frostbite. Dead plant parts show a dark or yellowish-green tissue color.

exception

An exception for cutting is the Farmer's hydrangea variety "Endless Summer". It is the only one to sprout again after pruning and cutting off inflorescences that have already formed in autumn. This means that more can be cut off, which is useful, for example, if it grows too powerful for you. You do not have to do without the flowering in that year, although it will start to bloom later after a strong pruning. If there is no need for heavy pruning, it should not be done so that the flowers provide a decorative eye-catcher as early and for as long as possible.

Incidentally, removing the first withered flowers in summer will encourage renewed budding.

Cutting group 2

The second group of hydrangeas are species that form their inflorescences from spring onwards. This only includes two hydrangeas with all different varieties:

• Panicles (Hydrangea paniculata)
• Snowball (Hydrangea arborescens)

Cut time

A cut can be made in autumn as well as in spring - and you can cut at both times. This is useful if you prune your summer flowers in late autumn anyway and in spring when the shoots are frozen or soaked from a damp winter.

The more you cut back, especially in spring, the more the hydrangeas in this group will sprout again. It is important here that the pruning in time carried out so that flowering can start early. The task should be completed by the end of February or the beginning of March at the latest.

This is how the cut works

Whether once or twice a year, the pruning should be done as follows:

• Shorten old shoots from the previous year down to the lowest pair of eyes - that has to stop
• Cut off thin and weak shoots on the shoot or near the ground
• Thin out the inside of the plant, completely remove old and dried-up parts of the plant
• In the spring, cut off especially the frozen parts of the plant
• Remove dead flowers in autumn