The florist's hydrangea produces towering white, blue, purple or pink pompons depending on the variety and soil type. The timing of flower pruning has often been a subject of discussion among gardeners. Some choose to prune them after flowering, others insist on keeping them until the following spring. Who is right?
Pruning time, the big question...
The Hydrangea genus is divided into several species that can be found in the garden, including the famous Hydrangea macrophylla, better known as the florists' hydrangea. Cultivated in pots on a terrace or a balcony, it is also planted in the garden in a half-shaded place where it brings its note of romanticism thanks to its big pompons from July to October. The hydrangea appreciates soils with a rather acidic tendency, its flowers can moreover change color passing strangely from bright blue to pink in too calcareous soil.
The pruning of hydrangea flowers is generally done in spring after the last big cold in regions with a harsh climate, that is to say in March-April before the vegetation wakes up. Be careful, however, because this hydrangea blooms on the previous year's stems. If the pruning is too drastic, you risk not taking advantage of its beautiful summer bloom! It is therefore not advisable to prune all the stems, but rather to opt for a selection that will ensure the renewal of the shoots without sacrificing the flowers. In regions where snow and frost are not uncommon, faded flowers protect buds and young shoots from the cold. Another advantage: they cover themselves with frost, bringing a fairy note to the garden!
In the mildest regions, pruning can be done just at the end of the flowering period, so that the flowering branches have more time to form.
How to prune hydrangea flowers?
- In regions with mild winters, proceed at the end of the blooming period by pruning the end of the flowering stems at a bevel just above a pair of buds. You can prune up to 25 cm of stem to give a harmonious ball shape to your shrub. If the subject is very old and less floriferous from year to year, cut the oldest branches at their base just above an eye if possible directed towards the outside.
- In regions with harsh winters, cut off spent flowers by pruning just above the first bud below the flower when there is no risk of frost in spring. Don't prune too low or your hydrangea may not bloom that year!
In both cases, take the opportunity to remove dead or damaged branches and weak stems that are entangled in the center of the shrub in order to aerate it. This operation limits the installation of parasites which particularly appreciate the plant clutter.
Don't forget to sprinkle a mixture of compost and ground horn powder at the foot of your hydrangea after pruning, to help restart the vegetation.
