When should you prune lavender indoors?

Pruning lavender grown indoors is less about responding to external seasons (like outdoor frost dates) and more about the plant's growth cycle in its controlled environment. However, you'll still generally follow a similar "after flowering" and "spring cleanup" approach, adapting to your plant's specific indoor conditions.

Here's when and how to prune lavender indoors:

1. Main Pruning: After Flowering (or When it Gets Leggy)

This is the most important prune to keep your indoor lavender healthy, bushy, and blooming.

• When: The ideal time is after its main flowering period has ended. Unlike outdoor lavender, which might have a distinct summer bloom, an indoor lavender might bloom at different times depending on its light and temperature conditions. Once the flowers have faded, browned, and look spent, it's time to prune.

  • If your indoor lavender isn't flowering much but is becoming leggy, spindly, or developing woody stems without much foliage, you can prune it to encourage bushier growth. The best time for this is typically in late winter or early spring (e.g., February to April), mimicking its natural outdoor dormant period before vigorous new growth begins.

• Why:

  • Encourages Re-blooming: Pruning removes spent flower stalks, signaling the plant to produce more flowers instead of seeds.

  • Maintains Compact Size: Essential for indoor plants to prevent them from becoming too large for their space or pot.

  • Prevents Woodiness: Regular pruning prevents the plant from becoming woody and leggy, ensuring more leafy, flower-producing growth.

  • Improves Air Circulation: Helps prevent fungal issues common indoors due to potentially lower air movement.

• How to Do It:

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

  • Cut Back by One-Third (or more for shaping): After removing flowers, cut back about one-third of the plant's green, leafy growth. For indoor plants that tend to stretch towards light, you might need to be a bit more aggressive (still staying within the green, leafy part of the stem) to maintain a compact shape.

  • Aim for Green: Always make your cuts above green foliage, ideally leaving at least 1-2 inches (2.5-5 cm) of green leaves above any woody stems. Lavender typically does not reliably regrow from old, bare woody stems.

  • Shape: Prune to create a neat, rounded, or mounded shape that fits your space.

  • Use Sharp, Clean Tools: Use small, sharp pruning shears or scissors. Sterilize them with rubbing alcohol between plants to prevent disease.

2. Light Tidy-Up / Spring Refresh

This is a lighter pruning to refresh the plant after its dormant period.

• When: In early spring (e.g., March or April), as the days lengthen and you notice vigorous new growth starting.

• Why:

  • Removes Dead or Weak Growth: Cut out any stems that appear dead, yellowed, or weak from its indoor "winter" period.

  • Refines Shape: A light trim helps maintain the desired form before the plant really takes off.

  • Promotes Bushiness: Encourages lateral branching for a fuller plant.

• How to Do It:

  • Inspect the plant for any clearly dead or spindly stems and snip them off.

  • Lightly trim any straggly growth to maintain its compact shape. Avoid removing too much new growth, as this is where new flower buds will develop.

Important Considerations for Indoor Lavender Pruning:

• Light is Key: Indoor lavender needs a lot of light (6-8 hours of direct sun or supplemental grow lights). Insufficient light will lead to leggy, weak growth that won't respond as well to pruning and won't flower abundantly. Pruning won't fix a lack of light.

• Humidity & Air Circulation: Indoors, ensure good air circulation around the plant to prevent fungal issues, especially after pruning.

• Watering After Pruning: After pruning, ensure the plant is adequately (but not over-) watered, as it will be putting energy into new growth.

• Repotting: Indoor lavender in containers may need repotting every 1-2 years as it grows. This is a good time to check the roots and potentially move to a slightly larger pot, ensuring excellent drainage.

• Don't Fear the Trim: Regular, moderate pruning is crucial for indoor lavender's health and appearance. It encourages the robust, compact growth you want in a houseplant.