We bought three lavender plants in spring and lost two by January. The problem was not cold — Lisbon winters are mild — but wet. Lavender does not die from temperature; it dies from soggy roots. The third plant, the one we put in a different pot with grittier soil and tilted slightly forward to drain, survived the winter and is now in its third year. The key turned out to be drainage, not warmth.
Why drainage saves lavender
Lavender evolved on rocky Mediterranean hillsides where rain runs off in seconds. Pot lavender in normal compost and water it the way you water a basil and you have created a swamp. Roots rot from the bottom up; the plant looks fine in November and is dead by mid-January. Add 40% horticultural grit to the compost, sit the pot on pebbles, and tilt the pot toward a drainage hole — the lavender survives.
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There is also a variety question. English lavender (Lavandula angustifolia) survives winters that French (L. stoechas) does not. The French is showier in summer and dies first in autumn. Pick English unless you live somewhere genuinely Mediterranean — and even then, the English is hardier. Within English, the smaller cultivars like Munstead overwinter better than the larger ones.
Pruning is the other half
Lavender that goes into winter unpruned dies more often than lavender that has been cut back. Late August is the right time — flower spikes have set and the stems are firm. Cut back to roughly two-thirds of the height, into woody stem but not the lowest grey wood. The plant goes into autumn compact, the stems are less likely to break in winter rain, and spring growth comes from a tighter base. We pruned the third plant; we forgot on the first two.
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“Lavender does not die from temperature; it dies from soggy roots.” — Mira
- English lavender, smaller cultivars. French is for showy summers, not honest winters.
- Soil: 60% compost, 40% horticultural grit. Builder's sand has lime; do not substitute.
- Tilt the pot 5° toward the drainage hole. Sit on pebbles to keep the saucer from puddling.
- Prune back two-thirds in late August. Tight base, fewer broken stems in winter rain.
What the bees and the kitchen do with the flowers
The first sign of a successful overwintering is bees in May. Lavender flowers attract honeybees, bumblebees, and a particular small dark solitary bee whose name we have never bothered to learn but who arrives every year and makes a slow ellipse around the balcony. Bees in the third week of May are the most reliable indicator of healthy lavender; we have started using their arrival as our cue to bring the basil out from indoors.
The flowers themselves we cut in late June, just before they would have lost their oils to summer heat. Three or four bunches per plant, hung upside-down in the kitchen for two weeks to dry. The dried flowers go into small linen sachets — three teaspoons per sachet — for the linen drawer and the cushion fillings. Two well-overwintered lavender plants supply us with two dozen sachets a year, which is more than we need and a steady supply of small gifts for friends.
Some flowers go into shortbread. Two teaspoons of dried lavender, one finely ground, one whole, into a standard shortbread mix. The result is unmistakably herbal in a way that surprises people who have not had lavender shortbread before. Most surprises are pleasant. The recipe is on a card in the kitchen drawer, next to a photo of the first plant we bought; the second plant came home the week we made the first batch.
Mistakes we made before settling on this method
We brought a plant indoors for winter once, thinking we were being kind. It died in three weeks of dry indoor air. Lavender wants outdoor cold and outdoor moisture, just not standing water. Indoor heating dries the foliage faster than the roots can supply moisture, and the plant dehydrates from the leaves down. Outdoor pot lavender, even in a Lisbon winter that touches three degrees overnight, survives because the leaves stay damp from rain and dew.
We also fed our first plant once a fortnight with a balanced liquid feed, which is the right schedule for tomatoes and the wrong schedule for lavender. The plant produced massive lush growth all spring and summer and was floppy by October. Floppy lavender is dead lavender by January. Now we feed once at planting, once in early March, and never else. Hungry lavender is happy lavender.
How to do it
Mix the soil before potting.
Half a bucket of compost, third of a bucket of horticultural grit, mix dry. The mix should fall through your fingers, not clump.
Pot with the crown above the rim.
Plant the lavender so its crown — the point where stems meet roots — sits 1 cm proud of the soil. Buried crowns rot.
Water once, then wait.
Generously, until water runs out the bottom. Then leave for two weeks. Lavender wants drought between waterings; a finger test in the soil is the schedule.
Late-August prune.
Two-thirds back. Sharp secateurs, no jagged cuts. The plant goes into autumn compact and recovers in spring.
Frequently asked
Can I use any compost?
What if my pot doesn't have a drainage hole?
Should I bring it inside in winter?
What if I forget to prune in August?
Can I propagate from cuttings?
Do bees damage the plant?
Why is my lavender turning grey?
Can I use the same pot for years?
In closing
Three lavender plants in their third year, all three flowering, all three pruned. The bees come in May. The flowers we cut and dry hang in the kitchen until October. The plants ask for very little — gritty soil, a tilt, a late-summer haircut — and pay back in fragrance. The rest of the balcony, by comparison, is needier than this.
