Pruning Lavenders is essential to promote more beautiful blooms and get a healthy, nicely shaped, mounded shrub that will last for years. If these rules are not respected, you might end up with a shabby, sprawling shrub.
Pruning Lavender differs with the type of Lavender you're growing
- Lavandula angustifolia - also called English Lavender, True Lavender or Common Lavender:
These Lavenders usually bloom once, but may enjoy a weak second flush after pruning. Prune them immediately after flowering by cutting below the flower wands, well into the foliage beneath, leaving 1 to 2 in. (2-5 cm) of foliage below the cut. Always make sure there are green leaves left on your lavender when you are done pruning. If all the green is gone, your Lavender will die. Expect your Lavender plant to live 20 years or more.
- Lavandula x intermedia - also called Lavandin:
These late season lavenders typically bloom in July or August and tend to last until late summer. Similarly to Lavandula angustifolia, prune them after flowering by cutting below the flower wands, well into the foliage beneath, leaving 1 to 2 in. (2-5 cm) of foliage below the cut - even if you have to sacrifice some late flowers. Expect your Lavender plant to live 20 years or more.
- Lavandula stoechas - also called Spanish Lavender or Butterfly Lavender:
Since these Lavenders flower almost continuously from spring to fall, it is not obvious to figure out the best time to prune them. The general rule is to prune them immediately after the first flowering by cutting below the flower wands, well into the foliage beneath, leaving 1 to 2 in. (2-5 cm) of foliage below the cut. Deadhead for the rest of the flowering season and continue to shape the foliage into a rounded, mound - including a gentle trim in late summer. Expect your Lavender plant to live 5 to 10 years.
- When pruning your Lavender, never cut into the woody part of your Lavender. Always make sure to leave the leafless wood intact, since cutting it could injure the plant. A good rule is to prune two leaf sets above the woody part. This will encourage stable growth and a healthier, thicker lavender plant.
- Always use a very clean set of pruning shears or secateurs that have been washed clean of dirt and disinfected with a bleach solution. Taking this precaution will help ensure that your Lavender plant doesn't pick up a bacterial disease. You should also make sure the shears are very sharp, so that they make a clean cut that will heal over quickly.
When to Prune Lavenders
Pruning once a year is great. Pruning twice a year is better. Pruning your Lavender will prevent your shrub from turning to wood. This is important because the parts of the plant that turn to wood will not produce new lavender stalks. Additionally, a woody plant is prone to cracking or rotting in winter.
- While pruning in spring can delay flowering, it is a good time to trim away dead or damaged parts. Prune your Lavender plants just as the new growth begins, cutting back as to leave some new shoots at the base of each branch.
- In late summer or early fall, after the last flush has faded, prune your Lavender stems down to an inch above the wood. This will provide better air circulation and prevent the snow to collect on the shrub and break it, or the wind to blow off weaker branches.
- Never prune just before winter as Lavender needs some foliage to protect it against the winter cold. If you prune too close to winter, your Lavender may die from the cold.