How do you winterize lavender plants?

Winterizing lavender plants is about helping them survive the colder months, especially if you live in an area with freezing temperatures. For beginners, the most important thing to remember is that lavender hates wet roots, especially when it's cold, and it generally doesn't like heavy pruning late in the year in colder climates.

Here's a beginner's guide to winterizing your lavender plants:

Why Winterize Lavender?

Lavender is a Mediterranean plant, meaning it loves sun and well-drained soil. It's built to handle dry, hot summers, but cold, wet winters can be tough on it. Winterizing helps protect its roots from freezing solid, prevents rot from too much moisture, and prepares it for healthy growth next spring.

Key Principles for All Lavender (In-Ground or Containers)

1. Excellent Drainage: This is the #1 rule for lavender, year-round, but especially in winter. Lavender roots will rot if they sit in soggy soil, which is even worse when the ground is cold or frozen.

   • In-ground: If your soil is heavy clay, ensure you planted your lavender in well-amended soil (mixed with sand or grit) or in a raised bed or mound.

   • Containers: Always use pots with drainage holes, and ensure they aren't sitting in saucers full of water.

2. Reduce Watering: As winter approaches and temperatures drop, lavender goes into a dormant or semi-dormant state. It needs much less water.

   • Allow the soil to dry out significantly between waterings. Overwatering in winter is a common way to accidentally kill lavender. Natural rainfall is often enough.

3. No Fall/Winter Fertilizing: Do not fertilize your lavender in the fall or winter. This can encourage new, tender growth that won't have time to harden off before freezing temperatures, making it very vulnerable to cold damage. Wait until spring when new growth starts.

Winterizing In-Ground Lavender

Your approach depends on how cold your winters get (your climate's hardiness zone).

• For Colder Climates (where temperatures regularly drop below freezing, e.g., Zones 5-7):

  • Pruning (Crucial Timing!): This is the opposite of what you might do in warmer climates. DO NOT perform a heavy prune in the fall. Heavy fall pruning encourages new, soft growth that will freeze and die, potentially killing your plant. Instead:

    • You can do a very light deadhead (just snipping off spent flower stalks) in late summer/early fall.

    • Save your main, shaping prune for early spring, after the last hard frost has passed and you see new green growth emerging. At that point, you'll cut back about one-third of the plant and remove any stems that clearly died over winter.

  • Mulching: Apply a 2-4 inch layer of coarse, well-draining mulch around the base of the plant in late fall, after the ground has started to cool or lightly freeze.

    • Good mulches: Straw, pine needles, or small gravel/pea gravel.

    • Important: Keep the mulch 2-3 inches away from the crown (base) of the plant stem. Piling it right against the stem can trap moisture and lead to rot. The mulch is to insulate the roots, not to smother the plant.

    • Avoid heavy, moisture-retaining mulches like shredded bark or wet leaves directly against the plant.

  • Snow Cover: If you get snow, it's actually a great insulator! A blanket of snow protects lavender from extreme cold and drying winds.

  • Wind Protection: In very exposed, windy areas, a temporary burlap screen on the side facing the prevailing winds can help prevent dehydration.

• For Milder Climates (where winters are generally above freezing, e.g., Zones 8+):

  • Pruning: You'll do your main prune in late summer to early fall (usually late July through September) after the main bloom has faded. This helps keep the plant compact and encourages bushiness for next year. Even here, avoid pruning so late that new, tender growth can't harden off before any unexpected cool spells.

  • Mulching (Optional/Light): You generally don't need heavy mulch for cold protection. If you mulch, use a thin layer (1-2 inches) of well-draining material (like gravel) to help retain soil moisture and regulate temperature, but still keep it away from the plant's crown.

  • Watering: Continue to reduce watering as temperatures cool. Focus on well-drained soil to prevent rot during any wetter winter periods.

Winterizing Container-Grown Lavender

Lavender in pots is more vulnerable than in-ground plants because the soil in pots freezes and thaws more quickly, and roots lack the insulation of the surrounding ground.

• Move to a Sheltered Location: This is the safest bet for most areas.

  • Move pots to an unheated garage, shed, or a covered porch where temperatures stay cool but above freezing (ideally 35-45°F / 2-7°C). Ensure some air circulation.

  • Water very sparingly in this dormant state, only when the top 1-2 inches of soil are completely dry.

• Bringing Indoors (Heated Home): This is trickier, as heated homes are often too warm and dry for lavender.

  • Choose the coolest, brightest spot possible (e.g., a south-facing window). Supplemental grow lights may be needed.

  • Drastically reduce watering (this is where most people go wrong indoors!). Allow the soil to dry out significantly between waterings.

  • Avoid placing near heat vents.

• Insulation for Pots (if left outdoors): If you absolutely must leave pots outdoors in colder areas:

  • Wrap the pot with burlap, bubble wrap, or blankets.

  • Place the pot inside a larger pot and fill the gap with straw or leaves for insulation.

  • Elevate the pot slightly off cold concrete with pot feet to improve drainage.

By understanding your climate's needs and following these steps, you can successfully winterize your lavender plants and enjoy their beauty for many years.