Who does not know them, the magnificent lavender fields of Provence. Lavender is one of the most popular scented herbs. So that it stays that way for many years, you don't just have to cut the withered flowers of the lavender.
In a nutshell
- Prune lavender usually twice a year
- the first time after flowering, the second time in spring
- second flowering possible after pruning in summer
- young plants can be cut back harder
- the more careful the cut, the healthier and more floriferous the lavender
Cut in time
Ideally, this subshrub is cut back twice a year, the first time when the lavender has faded. This flower cut should be done around the middle/end of July, but no later than the beginning of August. Immediately after flowering, the plants begin to form seeds. If you cut in time, seed formation can be prevented and the plants stimulated to form a second flower.
The summer cut should not be made later, because then the shoots can no longer mature properly by winter and the plants die over the winter. The time for the second or main cut is in early spring, even before the first new shoots appear. It is usually early/mid-April as soon as no more frost is to be expected.
Notice: If the lavender has not yet faded in August, it is advisable to wait until spring to cut it. On the cutting day it should be as dry as possible, overcast and not sunny.
Flower pruning in summer
When the lavender has faded, it's time for the summer cut. Neither too much nor too little should be cut. It is recommended to follow the so-called one-third rule.
- shorten the stems by about a third
- if the length of the shoots allows it
- Do not cut into old wood or parts that are already woody
- no more shoots and flowers formed there
- Cut only in the green area
- always above a well-developed pair of leaves
- Shorten young plants a little more
- about halfway
If older lavender has faded, a little finesse is required. The stems are usually woodier and stronger and the plants more woody. Here you first remove only the withered inflorescences. Then you cut them back a maximum of ten centimeters. After the flowers are cut, the lavender will sprout again.
Tip: If the optimal time for the summer pruning has been missed, the withered inflorescences can be cut off until September. Further pruning measures should then be postponed to spring.
Main cut in spring
This cut is a shape or grooming cut. You can use the two-thirds rule here. So you can cut the lavender a little more generously. However, you should not cut down to the old wood here either, but only the soft shoots.
The cut is made just above the old shoots from the previous year. Woody, dried up and frozen parts of the plant that no longer form new shoots can also be cut out. The main pruning ensures a nice, compact shape throughout the summer and prevents progressive woody growth in the lower part of the plants.
The right tool
The cutting tools used should generally be sharp enough. With knives it is important to ensure that they have a smooth and not serrated blade. The latter could leave frayed cut edges. As a result, the healing process and drying of the cut would take longer, which in turn increases the risk of infection with pathogens. For this reason, it also makes sense to disinfect the tools before and after the cut, for example in 70 percent alcohol.
frequently asked Questions
Why should you prune lavender at all?Lavender is a semi-shrub and therefore tends to become woody. If you do without any pruning measures with these plants, they will become more and more woody and bare over the years. The woody parts form hardly any new shoots, even after a strong pruning. The flowers become fewer and fewer and the entire shrub may fall apart. A regular trim can prevent all of that.
Does a rejuvenation cut make sense in the case of heavy woody growth?Such a rejuvenation cut is difficult and in most cases not crowned with success. A large part of the shrubs does not survive this procedure. If you still want to try it, you should do it in small steps over several years.
Can you still cut lavender in autumn?It is generally not advisable to cut back lavender in autumn. It could cause considerable damage to the plants, and winter protection would also be lost. The new shoots would not mature until winter and threaten to freeze to death later.