If you want lavender to grow compactly and bloom abundantly even after several years, you need to prune it regularly. Here’s how to do it.
Lavender originates from the western Mediterranean and is grown agriculturally in Italy, Spain and France for the production of perfume. With the help of machines, lavender farmers cut off the flower shoots in summer to produce the fragrant lavender oil. Provence in particular is known for its almost endless lavender fields. In home gardens, the common lavender (Lavandula angustifolia) is also very popular as an ornamental plant, and you also need to prune your lavender regularly so that it remains compact and produces many flower shoots each year.
When to cut lavender?
There is an important pruning date for lavender and a less important one. The important one is in spring: between the end of February and mid-March. That is, before new shoots appear, you should cut back all flower shoots from the previous year to short stubs. In this way, the lavender remains compact and forms many new flower shoots until summer. In long, cold winters, it is better to wait a little longer before pruning, because after that there should be no more permafrost, if possible.
The second pruning date for lavender is in July or August, as soon as the half-shrub has faded. Now cut out all the old inflorescences, so that the half-shrubs do not put unnecessary energy into the formation of seeds. In addition, early summer pruning often sprouts a few new flower shoots until autumn.
Why do you need to prune lavender every year?
To avoid lavender care mistakes, remember: lavender needs to be pruned vigorously every year to keep it compact. If the plants are left to grow uncut for several years, they will fall apart and become bald from the bottom up. The woody branches will not form new shoots on their own and will be reluctant to sprout even after pruning.
When pruning lavender, follow the so-called “one-third-two-thirds rule”: after flowering, use hedge clippers to cut back all shoots by about one-third so that all wilted inflorescences are removed, but the leafy branch sections remain mostly intact. A heavier pruning by two-thirds is then done in the spring so that the plants remain compact and branch well. The optimal pruning date is as soon as no more permanent frosts are expected.
Also, when pruning in the spring, make sure to keep a short section of last year’s shoots with a few leaves on them at a time so that the lavender bushes will sprout well again.
Is it possible to rejuvenate old lavenders?
Old, fallen-apart lavender bushes with sparse, woody main shoots can’t be saved by heavy rejuvenation pruning in most cases. But as so often in gardening life, when in doubt, it comes down to trial and error. Success seems to depend heavily on the date of pruning, as some amateur gardeners report that after radical pruning in June/July, their old lavender shrubs sprouted new shoots that same year and flowered beautifully the next year.
The right location for lavender
Lavender reaches a height of 30 to 60 centimeters (12 to 24 in). It is often thought to be a perennial, but botanically it is a subshrub. The annual shoots remain herbaceous at first and become woody from below as the years go by. Overall undemanding, sun-loving lavender prefers dry, lean soil and therefore should not be fertilized. Incidentally, as a Mediterranean plant, lavender is quite sensitive to frost, especially if it grows in very nutrient-rich, moist soil. The ideal location is a south-facing place protected from the wind in front of a house wall. The best time to harvest lavender is just before it blooms.