Overwintering lavender and winter savory

(Question)

How do I help small lavender and winter savory survive Toronto winter? Thank you.

(Answer)

Thank you for contacting the Toronto Master Gardeners with your inquiry. There is nothing more beautiful than observing a field of lavender in full bloom.

Mature lavenders form dense mounds of foliage, ranging from grey to green and from 30 to 60 cm tall, depending on the species. Lavender ( USDA zone 5-9) will thrive when planted in full sun on a well-drained site. Well-drained soil is the key to lavender surviving our cold winters. They will tolerate dry, poor soil however, an annual top dressing of compost and occasional watering during very dry spells is welcome. Make sure to avoid over-fertilizing with high nitrogen fertilizers.

Lavender will bloom from June-July. If lavender is deadheaded after the first bloom period you will be rewarded with a second smaller bloom later in the summer. The old stems from the second bloom phase can be left on and then removed in the spring.

Avoid heavy pruning of lavender after late August so that the plants are able to harden before winter. Spring is the best time to shape lavender plants and remove winter-damaged tips. However, be sure to wait until you observe new growth breaking from the old stems; sometimes this could be as late as early June.

Lavender is classified more as a subshrub rather than an herbaceous perennial since the new growth breaks from old woody stems. Many gardeners lose their lavender plants by cutting them completely down in autumn or early spring as they do their herbaceous perennials.

This plant has a tendency to grow straggly with age therefore; they should be sheared back every 2-3 years in the spring (once new growth is observed) to about 15-20 cm to maintain a more compact, vigorous plant.

Even with proper pruning and site location losses can occur during severe winters without consistent snow cover, which is what we experienced this past winter.

That being said, I have grown 25 lavender plants successfully for the past 6 years in the Markham area simply by following the above steps.

Here’s to your continue enjoyment of this lovely subshrub.

Winter savory (Satureja montana) is a semi-evergreen bushy perennial that grows to about 15 inches tall. Plant winter savory in full sun in well-drained, sandy soil that has a pH of 6.3-7.3. Both summer and winter savory can be started indoors as early as 6-8 weeks before the last frost date. The seeds of winter savory can be slow to germinate. This herb requires regular even watering until it is established but once established it can be kept on the dry side.

Winter savory is hardy to -10C ( USDA zone 6) and as a result, it is considered a tender perennial in our zone 5 area. The good news is that you can grow winter savory in a container, make sure the container is at east 6” deep and wide and overwinter the container grown savory in an unheated garage.

Here are some excellent articles on growing herbs: Growing Herbs for the Home Gardener, Winter Savory, Winterizing the Herb Garden