Preparing lavender for winter in cold climates (generally USDA Zones 5-7) is crucial for its survival, as lavender prefers warmer, drier Mediterranean conditions. The main goals are to protect the roots from extreme cold, prevent crown rot from excessive moisture, and shield the plant from harsh winter winds.
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Bring the lavender idea from this article into your home with these Island Lavender favorites.
Here's how to prepare your lavender for winter in cold climates:
1. Choose the Right Variety:
This is the first and most important step. Some lavender varieties are much more cold-hardy than others.
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English Lavender (Lavandula angustifolia): Varieties like 'Munstead', 'Hidcote', 'Lavender Lady', and 'Vera' are the most cold-hardy, typically surviving down to Zone 5, and sometimes even Zone 4 with proper protection.
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Lavandin (Lavandula x intermedia): Hybrids like 'Grosso', 'Provence', and 'Phenomenal' are also quite hardy (Zone 5-9) and vigorous.
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Avoid Tender Varieties: French (Lavandula dentata) and Spanish (Lavandula stoechas) lavenders are generally only hardy to Zone 8 or warmer and usually need to be brought indoors in colder climates.
2. Pruning (Crucial Timing!):
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In Colder Climates (Zones 5-7): DO NOT perform a heavy prune in the fall. Heavy fall pruning stimulates new growth that will not harden off before winter, making it extremely vulnerable to frost damage and potentially killing the plant.
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Instead, wait until early spring (after the last hard frost and when new green growth begins to appear at the base) to do your main prune. At that time, you can cut back about one-third of the plant, removing any winter-killed stems and shaping it.
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A very light tidy-up to remove spent flowers (deadheading) can be done in late summer, but avoid deep cuts into the woody part of the plant.
3. Ensure Excellent Drainage:
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This is paramount year-round, but especially vital in winter. Lavender cannot tolerate "wet feet," and frozen, waterlogged soil leads to root rot, which is the number one killer.
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Planting Site: Choose a location with naturally well-draining soil, ideally a raised bed or a gentle slope.
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Soil Amendment: If you have heavy clay soil, amend it generously with coarse sand, grit, or small gravel before planting.
4. Mulching (for Root Insulation):
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Apply a 2-3 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.
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Best Options: Straw, pine needles, or small gravel. These allow for air circulation and don't hold excessive moisture.
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Crucial: Keep the mulch 2-3 inches away from the crown (base) of the plant. Piling mulch directly against the stems can trap moisture, promote rot, and invite voles or other pests to nest, leading to damage. The goal is to insulate the roots, not suffocate or rot the crown.
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Avoid: Heavy, moisture-retaining mulches like shredded wood mulch, peat moss, or excessive piles of leaves, especially in areas with wet winters, as these can hold too much moisture.
5. Wind Protection:
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Harsh, dehydrating winter winds can cause significant damage to lavender, leading to "winter burn."
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Natural Windbreaks: If possible, plant lavender in a location naturally shielded from prevailing winter winds, such as against a south-facing wall (which also provides radiant warmth) or near taller, evergreen shrubs.
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Artificial Barriers: For exposed plants, consider installing a temporary windbreak made of burlap or specialized windbreak fabric on the windward side. Ensure it allows for some air circulation.
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Snow Cover: If you live in an area with consistent snow cover, rejoice! Snow acts as a fantastic natural insulator, protecting the plants from extreme cold. However, heavy, wet snow can break branches, so gently brush off excessive accumulations if needed.
6. Watering (Reduce Significantly):
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As winter approaches and temperatures drop, gradually reduce watering. Lavender enters dormancy and needs very little moisture during the cold months.
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Stop Watering Before Hard Freeze: Ensure the soil is relatively dry before the first hard frost. Soggy soil that freezes can lead to root rot.
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Rainfall and snowmelt are usually sufficient for established plants in winter. Only water if you experience a prolonged dry spell with no snow cover.
7. Container-Grown Lavender:
Lavender in pots is much more vulnerable to cold, as the roots are exposed to colder temperatures and the soil freezes solid faster.
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Move to Sheltered Location: The most effective strategy is to move potted lavender to an unheated garage, shed, cold frame, or covered porch before temperatures consistently drop below freezing. Temperatures should ideally stay cool (e.g., 35-45°F or 2-7°C) but above freezing.
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Light: Provide as much light as possible, even indoors. A cool, bright windowsill or supplemental grow lights are beneficial, though plants will be dormant.
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Water Sparingly: Water very, very sparingly, only when the top inch or two of soil is completely dry. Overwatering is the biggest risk indoors.
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Bury the Pot: In moderately cold zones, you can dig a hole in the ground and bury the entire pot (up to the rim) in a well-draining spot. This leverages the insulating power of the earth.
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Group Pots: Grouping potted plants together can provide mutual insulation.
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Insulate Pots: You can wrap pots with bubble wrap, burlap, or old blankets for added insulation.
By implementing these strategies, you can significantly increase the chances of your beautiful lavender plants surviving the winter and thriving again in the spring.
Lavender Farm in Door County Wisconsin. You can buy lavender products online at islandlavender.com
