5 Tips For Protecting Your Lavender This Winter

I absolutely love lavender. I love the floral, yet slightly astringent scent that clings to your skin when you brush by it. I love the silvery foliage that stands out among the beds of green and brown. I love that it is covered in bees for most of the summer and fall.

Rather unsurprisingly, this famous herb has not always loved me back. The Mediterranean native plant does not love the heavy clay soil of northeast North America. It definitely does not love the months of freezing temperatures found in my zone 4 garden. But, after several seasons of trial and error (lots of errors!), I’m pleased to report there is finally some growing in my garden.

Plant It In a Pot

For some gardeners, bringing their herbs indoors during the coldest months is a good way to skip the “will it, won’t it” worrying over whether it will survive until spring. The simplest solution? Put it in a pot! Growing in a container means you have full control over climate and soil.

Choose a container with drainage holes and fill it with a sharply drained mixture of vermiculite, horticultural sand, and just a touch of compost. Lavender prefers gritty, nutrient-poor soil that is slightly alkaline. Standard potting soil that you use for veggies or houseplants will be far too rich for these Mediterranean natives.

Once winter arrives, move the container to a sheltered location or bring it right inside. Although the plant will not be actively growing during the winter, it still needs plenty of light to mimic its native climate. Place the plant in a very bright room that stays cool (40-65°F or 4-18°C). Water deeply but then allow the soil to dry out completely between waterings.

Protect It From Wind

Wind is a tricky bit of climate for gardeners to contend with. We talk about temperature and precipitation A LOT, but we often forget to take wind into account! It doesn’t factor into hardiness maps, and it can vary dramatically within just a small area. Even a gentle change in elevation can mean the difference between a gusty garden and one that is relatively calm.

Winds can be very drying and can easily wick moisture from leaves and stems. Plants can easily dehydrate if the ground is already frozen and water intake by roots is reduced. Plants that are exposed to freezing winds without any snow cover are especially at risk.

There are several ways to protect your lavender from the winter wind. Planting near a structure or cluster of trees is one solution, although you’ll need to make sure this sun-loving herb isn’t stuck in deep shade. Strategically-placed windbreaks, such as fences or hedges can act as much-needed shelter. A temporary covering of frost cloth or loosely placed burlap can provide protection during the winter months.

My favorite? A layer of dried leaves tucked around the plant. Straw, coconut coir, or even evergreen boughs are also effective mulch materials. These lightweight mulches will insulate against cold winds without trapping water and risking rot.

After the first hard freeze, apply a 2-6 inch layer of mulch around the plant. Too much mulch early in the fall may actually decrease an herb’s winter hardiness. Remove the mulch or frost cloth as soon as spring temperatures arrive.

Ensure Well-Drained Soil

Lavender does not grow well in heavy clay or waterlogged soils. Poorly drained soil leads to yellowing foliage, followed by root rot. Waterlogged soil plus cold temperatures? Well, that spells a definite death sentence for this plant.

Plant your perennial in lightweight soil that drains easily. I finally learned that lavender was happiest at the higher end of my gently sloping backyard. There, it gets plenty of sun and keeps its feet dry.

Gardeners in cold climates may need to put a little extra effort into amending heavy soils. Add coarse-textured compost and bark mulch prior to planting. Lavender doesn’t need much in terms of soil fertility (and actually prefers nutrient-poor conditions), but adding some garden lime can help raise the pH. This plant grows best in slightly alkaline conditions, with a pH between 6.0 and 8.0.

If your native soil is less than ideal and no amount of amending will improve it anytime soon, consider planting in a raised bed. You’ll avoid standing water and have control over the soil quality.

Plant the perennial slightly above the soil line, so the woody crown sits up off the soil. Do not plant too deeply. After the lavender is in the ground, consider mulching with inorganic mulches such as gravel or pea stone. This helps keep the crown dry, and it prevents excess moisture from forming and causing disease or rot.

Prune Properly

Pruning for a woody plant like lavender is especially important. It encourages proper air circulation and keeps the plant from getting “too woody” and splitting at the center. Lavender flowers on new growth, so pruning promotes flowering and helps the plant retain its lovely rounded shape in the landscape. Pruning also ensures that the plant can withstand heavy snow without breaking.

To prepare your lavender for winter, prune immediately after flowering, and at least 4-6 weeks before a major freeze. For many of us cold climate gardeners, this means by late August or early September. Cut off about two-thirds of the plant’s height or just above the bottom two sets of leaves. Snipping off a few woody stems to tidy the shape of the plant is fine, but take care not to cut directly into the woody crown of the plant.

If you missed the pruning window, don’t try to squeeze it in during the final weeks of fall. This can stimulate new growth during a time when your plant should be powering down for the winter. Wait until next spring before pruning.

Choose a Hardy Type

Most of the plants available to home gardeners can be classified as French types (L. dentata) and English types (L. angustifolia). Both types are fantastically fragrant, and require sharp, well-drained soil and drought-like conditions. However, the English varieties are more cold-hardy than their French counterparts, which prefer a much milder climate. If planted in well-drained soil and full sun, a healthy English lavender is hardy to zone 4 or 5, while French types prefer zone 7 and warmer.

Somewhere in between those two types is Lavandula x intermedia, a hybrid cross between English and Portuguese lavender. Frequently referred to as “lavandin”, these types are known for their disease resistance, cold hardiness down to zone 5, and ability to withstand a bit more humidity than other types.

There are 45 known species and over 450 different varieties of lavender. If you garden in a particularly cold climate, consider choosing one of these hardier types.

‘Munstead’

A compact herb that stands just 12-18 inches tall, ‘Munstead’ is popular for its bright purple blooms. This is an English type that is hardy to zone 5, although, with proper protection from the wind and well-drained soil, it can survive in colder climates.

‘Hidcote’

‘Hidcote’ is a classic English lavender that boasts cool blue-purple flowers and silver-gray foliage. Another compact variety, ‘Hidcote’ stands 14-20 inches tall and is hardy through zone 5.

‘Phenomenal’

An extremely resilient and cold-hardy lavandin hybrid, ‘Phenomenal’ tolerates slightly more humidity than other types. This is the only variety that has reliably persisted in my freezing Vermont yard. It features sweetly-scented mounds of silvery foliage and lovely purple-blue spikes of flowers. 

‘Vera’

Exceptionally fragrant ‘Vera’ is thought to be one of the original “true English” lavenders, and has been valued for its medicinal properties for centuries. ‘Vera’ is also quite tolerant of cold temperatures. This English variety is hardy to zone 5 and features dark purple blooms and narrow leaves. It stands 16-20 inches tall.

‘Provence’

Another hardy lavandin hybrid, ‘Provence’ tolerates cold and humidity well. This is a large variety that can easily reach 2 feet tall and wide. Give it plenty of space to ensure proper airflow between stems. ‘Provence’ has heavily-scented, pale purple flowers and is hardy through zone 5.