Not every lavender plant can be left outside in winter. Of the estimated 25 to 30 lavender varieties, only the true lavender (Lavandula angustifolia) native to the mountains is hardy and can remain outdoors with proper protection. All other lavender varieties overwinter best under cold house conditions in a pot.
Protect outdoor lavender from frost
As a rule, winter-hardy lavender can easily overwinter outside in the garden. However, the prerequisite for this is a sunny and sheltered location, for example, on a warming wall of the house. Also, it must not be draughty, because the plant does not like strong wind at all. In addition, you can additionally protect the plants from frost with protective mats or brushwood. Covering further has the advantage that precipitation and moisture can not drown the drought-loving lavender. Only a blanket of snow is advantageous, because it protects the plants from the cold. Paradoxical as it may sound, lavender dries out due to lack of moisture, especially in winter, because the sun on frosty days evaporates any moisture faster than the plant is able to absorb the water. Provided that the soil is frost-free, you can water the lavender if necessary – but be careful, in any case, do not allow waterlogging to form.
Overwinter lavender in pot
Potted lavender overwinters best in a bright, cool location inside a home. Heated rooms such as the living room should be avoided, however, as the plants require winter dormancy. Temperatures around 10 to 12 °C are optimal. In winter, lavender needs regular but little water and should not be fertilized. Finally, in the spring, provided the weather is suitable, you can put the plants back outdoors for hours at a time starting in March to prepare them for the new growing season.
Tips & Tricks
Unlike many other woody plants, lavender should not be pruned in the fall. If possible, the last pruning should be done no later than the beginning of August.