Overwintering container lavender

(Question)

I have a Munstead lavender plant in a container on my north facing balcony in Toronto ON, which has done really well this summer and I wanted to bring it indoors for the winter. I don’t get any direct sunlight indoors but have a spot where the indoor plants like the peace lily have thrived. Will it survive? Or are there other steps that I need to take?

Thanks

(Answer)

Different plants may not thrive in the same environment.  For example, the peace lily requires bright indirect light – a north- or east-facing window would be a good option for this plant.  On the other hand, Munstead lavender generally needs 6-8 hours of sunlight daily, and a south-facing window would be best.  I’m puzzled that your plant has thrived on your north-facing balcony.  Somehow, it must be getting sufficient sun!

It’s a good idea to move it indoors for the winter.  Before the first frost, start to acclimatize the plant to its new (less sunny) indoor environment, by moving it inside for a couple of hours daily for a week – increase the time it spends indoors gradually.  Start to water less frequently than you’ve done throughout the summer.

  • Temperature: Keep the pot in a cool room, away from drafts. The plant can tolerate a nighttime temperature as low as 5 degrees C (40 degrees F) and warm daytime temperature up to 18 degrees C (65 degrees F). Keep the plant away from heaters.
  • Water: The lavender will not be actively growing over the winter, so do not water it often and let the top 2.5 cm (1 inch) of soil dry out between waterings. Too much watering risks root rot.
  • Light:  As noted above, the lavender needs lots of light – try to keep it in a bright spot on the windowsill. If the plant does not do well, a grow light would help supplement the natural light.
  • Space: Give the plant lots of space so that air circulates well around it.
  • Soil: The soil should be well-draining.  Check the container to make sure the soil has not compacted too much over the growing season.  If it has, you can remove and replace some of the soil with potting soil.
  • Fertilize: Do not fertilize over the winter. Only fertilize once it starts showing signs of growth in the spring.

One of the main concerns in overwintering your lavender is to ensure that it gets enough light indoors. In any event, it will probably look quite sad and spindly over the winter, but should start to revive come spring.

All the best in keeping your lovely lavender happy!

October 1 2023