When should you prune lavender?

Pruning lavender is one of the most important things you can do to keep your plant healthy, compact, and blooming beautifully year after year. For beginners, understanding when and how to prune is key to success.

Generally, you'll want to prune lavender twice a year: once after its main flowering period, and a lighter tidy-up in the spring.

1. The Main Pruning: After Flowering (Late Summer to Early Fall)

This is the most crucial and often the most significant pruning your lavender will receive.

• When: The ideal time is after the main flush of flowers has faded. You'll notice the blooms becoming spent, brown, or leggy. This usually happens in late summer to early fall (e.g., late July through September, depending on your specific climate and the lavender variety).

  • Don't wait too late: It's important to finish this prune before the truly cold weather sets in. This gives the plant enough time to put on some new growth that can harden off before any potential hard freezes. Pruning too late can stimulate tender new growth that is vulnerable to cold damage.

• Why:

  • Encourages More Blooms: By removing spent flower stalks, you prevent the plant from putting its energy into producing seeds. Instead, it redirects that energy into developing new foliage and more flower buds for the following season.

  • Maintains Shape and Prevents Woodiness: Lavender has a tendency to become woody and leggy over time if not pruned regularly. This main prune helps keep the plant compact, bushy, and prevents it from sprawling. Woody stems produce fewer flowers.

  • Improves Air Circulation: A well-pruned plant has better airflow, which can help prevent fungal diseases, especially in humid conditions.

• How to Do It:

  • Remove All Spent Flower Stems: Cut off all the faded flower spikes.

  • Cut Back by One-Third: After removing the flowers, look at the overall size and shape of your plant. You'll want to cut back about one-third of the current season's green, leafy growth.

  • Aim for Green: This is a golden rule for lavender. Always make your pruning cuts into the green, leafy part of the stem. Typically, leave at least 1-2 inches (2.5-5 cm) of green leaves above any old, bare, woody stems. Do NOT cut into old wood that has no green leaves or active growth. Lavender does not reliably regrow from old wood, and cutting too far back can kill that section of the plant or even the entire plant.

  • Shape: Prune to maintain a neat, rounded, or mounded shape. This not only looks aesthetically pleasing but also allows sunlight and air to reach all parts of the plant.

  • Use Sharp Tools: Always use clean, sharp bypass pruning shears. Clean cuts heal faster and reduce the risk of introducing diseases.

2. The Spring Cleanup (Early Spring)

This is a lighter pruning primarily for tidying up the plant and removing any winter damage.

• When: This prune should happen in early spring, after the last significant frost has passed and you begin to see definite signs of new green growth emerging from the base of the plant (typically March to April).

• Why:

  • Removes Dead or Damaged Growth: Cut out any stems that are clearly dead, brittle, or show signs of winter damage. Cut these back to healthy green growth or to the base if entirely dead.

  • Refines Shape: A light trim can help refine the shape of the plant before it really begins its vigorous growth for the new season.

  • Promotes Bushiness: It encourages more branching, leading to a fuller plant.

• How to Do It:

  • Inspect the plant closely for dead, diseased, or spindly stems and remove them.

  • Lightly trim any straggly or wayward growth to maintain the desired compact shape. Be careful not to remove too much new, active green growth, as this is where the season's first flowers will develop.

3. Ongoing Light Deadheading (Optional)

• When: Throughout the blooming season, as individual flower spikes fade.

• Why: While not a heavy prune, deadheading (removing just the spent flower heads) can encourage some lavender varieties (especially those that tend to re-bloom, like French or Spanish lavenders) to produce additional flushes of flowers. It also keeps the plant looking neat.

• How to Do It: Simply snip off the faded flower stalks just above the first set of leaves or where the flower stem meets the main foliage.

Important Pruning Tips for Beginners:

• The Golden Rule: Never Cut into Old Wood (Unless Dead/Damaged): This cannot be stressed enough. Always aim for green growth.

• Start Young: Begin pruning lavender plants when they are young. Pinching off tips of new growth on young plants helps them develop a dense, bushy shape from the start, preventing them from becoming woody too quickly.

• Don't Fear the Pruners: While the "no old wood" rule is critical, don't be afraid to prune. Regular pruning, even if it feels like a lot, is what keeps lavender healthy and productive.

• Sharp, Clean Tools: Always use clean, sharp bypass pruning shears. This prevents jagged cuts that can invite disease and helps the plant heal faster.

• Observe Your Plant: Pay attention to how your specific lavender variety grows and responds to pruning. Some may be more vigorous than others.

By following these simple guidelines, even as a beginner, you'll be able to keep your lavender thriving and beautiful for many years.