Is French lavender an indoor plant? Not by nature, but you can keep one inside for short stretches. The plant needs 6+ hours of direct sun and cool winter rest that most heated homes do not offer. Treat it as a part-time guest, not a year-round houseplant.
I tried growing lavender indoors for one full year as a test. My plant sat by a south-facing window the whole time. It looked fine for the first three months. By month six the leaves turned gray and dry. By month nine the plant was dead and I had to start over.
Most homes fail French lavender on three fronts. The light is too weak. The air is too humid. The winter air is too warm. A plant from the dry hills of France cannot adapt to a damp warm living room with low light for long. Indoor lavender care must fix all three of these gaps.
The light gap is the hardest one to close. A bright south window gives about 2 to 4 hours of usable sun. The plant needs 6 hours or more. Add a full-spectrum LED grow light set on for 12 hours per day. Place it within 6 inches of the plant for the best results.
South Window With Grow Lights
- Window choice: Pick the south-facing window that gets the most direct sun all day. East and west windows do not give enough light hours to keep the plant alive long term.
- Light add-on: Hang a full-spectrum LED grow light about 6 inches above the plant. Run the light for 12 hours per day to push total light past the 6-hour mark.
- Humidity fix: Place the pot away from kitchen and bath rooms to avoid the damp air that breeds rot. Aim for room humidity below 50% at all times.
Cool Sunroom or Sun Porch
- Temperature: Keep the room at 40 to 55°F (4 to 13°C) during winter to give the plant the cool rest it needs to bloom well the next spring season.
- Light source: A sunroom with glass on three sides catches sun from many angles. This works far better than one window inside a heated living room space.
- Best use: Treat the sunroom as winter shelter only. Move the plant back outdoors in May when nights stay above 40°F (4°C) for a full week or longer.
Bright Unheated Porch or Garage
- Setup: A bright porch or garage with a south-facing window works well in zones 6 and 7. The plant gets cool rest but stays above the freezing threshold of 19°F (-7°C).
- Watering: Cut water to once every 3 to 4 weeks during the cool rest period. Soggy soil in cold air leads to root rot faster than any other indoor problem.
- Spring move: Harden the plant off over 7 to 10 days in mid-May before you set it back in the full sun spot in your garden bed or container.
Be honest about what you can offer a french lavender houseplant before you buy one. If your home stays warm and humid all winter, the plant will fade and die within a year. If you have a cool sun porch or a heated garage with a south window, you can keep one alive for years with care.
When I moved to a house with a sun porch, my indoor track record changed. The same plant lived for four years with no decline. The trick was the cool air that ran 45°F (7°C) all winter long. The plant rested through the cold months and bloomed hard each May.
Use indoor space as a winter holding zone, not a year-round home. Buy a sturdy pot with great drainage. Run a grow light for at least 12 hours per day. Keep the air cool and dry through winter. Move the plant back outdoors as soon as the spring nights warm up.
Read the full article: French Lavender: Complete Grower Guide
