Who does not know them, the magnificent lavender fields of Provence. Lavender is one of the most popular fragrant herbs. To keep it that way for many years, you need to cut not only withered flowers of lavender.
- Cut lavender usually twice a year
- the first time after flowering, the second time in the spring
- after flower pruning in summer second flowering is possible
- young plants can be cut back more
- the more careful the pruning, the healthier and more flowering lavender will be
Cut in time
Ideally, this half shrub should be cut back twice a year, the first time when the lavender has faded. This flower pruning should be done around mid-late July, but no later than early August. Immediately after flowering, the plants begin to form seeds. If pruned in time, seed formation can be prevented and the plants can be encouraged to form a second bloom.
Summer pruning should not be done later, because then the shoots may not mature properly until winter, and the plants may die over the winter. Time for the second or main pruning is in early spring, before the first new shoots appear. Usually it is early/mid-April, as soon as no more frost is expected.
Note: If the lavender has not yet bloomed in August, it is advisable to wait until spring before pruning. On the day of pruning, it should be as dry, overcast and not sunny as possible.
Flower pruning in summer
Once the lavender has faded, it is time for summer pruning. Neither too much nor too little pruning should be done. It is recommended to follow the so-called one-third rule.
- to do this, shorten the stems by about a third
- if the length of the shoots allows it
- do not cut into the old wood or already woody parts
- no more shoots and flowers formed there
- Cut only in the green area
- always above a well developed pair of leaves
- cut young plants a little more vigorously
- about up to half
If older lavender has faded, a little tact is required. The stems are usually woodier and stronger, or the plants are more woody. Here, you first remove only the withered inflorescences. Then cut them back by a maximum of ten centimeters. After cutting the flowers, the lavender will sprout again.
Tip: If the optimal time for summer pruning has been missed, the wilted inflorescences can still be cut off until September. Further pruning should then be postponed until spring.
Main pruning in spring
This pruning is a shaping or maintenance pruning. Here you can proceed according to the two-thirds rule. You can cut the lavender a little more generously. However, you should not cut into the old wood, but only the soft shoots.
The cut should be made just above the old shoots from the previous year. Woody, dried and frozen parts of the plant, which no longer form new shoots, can also be cut out. The main pruning ensures a beautiful, compact shape throughout the summer and prevents progressive lignification in the lower part of the plants.
The right tool
The cutting tools used should generally be sharp enough. For knives, make sure they have a smooth blade and not a serrated one. The latter could leave frayed cut edges. This would result in the healing process and drying of the cut taking 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 cutting, for example in 70% alcohol.
Frequently asked questions
Why cut lavender at all?
Lavender belongs to the semi-shrubs and, consequently, tends to lignify. If these plants are not pruned at all, they will become more and more woody and barren over the years. The woody parts form hardly any new shoots, if any at all, even after vigorous pruning. The flowers will become fewer and fewer and eventually the entire shrub will fall apart. Regular pruning can prevent all this.
Does rejuvenation pruning make sense when there is a lot of woodiness?
Such rejuvenation pruning is difficult and in most cases not crowned with success. A large proportion of shrubs do not survive this procedure. If you still want to try, you should do it in small steps over several years.
Can lavender still be pruned in the fall?
Pruning in the fall is generally not recommended for lavender. It could cause considerable damage to the plants, and winter protection would also be lost. The new shoots would not mature until winter and would be in danger of freezing later.