Herbs are notoriously finicky in the house in the winter. It’s not their fault. There’s not enough light for them, and it’s either too dry (for some) or too wet (since many of us tend to over-water and therefore love our plants to death!)
Lavenders can take the dryness, being bred for exactly that sort of condition. Both their silvery leaves and the places they might normally grow “in the wild:” the Mediterranean with its sandy soils and salty air show that it is a tough plant that can take a lot of abuse.
So why then, does it struggle in conditions that gardeners usually give it? Good soil and abundant water? Well, that’s perhaps why–we are loving it to death–we are spoiling it too much, drowning it and probably over-feeding it too. Not good.
So what is that gardener to do? Well, short of neglecting the plant completely, because that isn’t necessarily a recipe for success either, the trick to succeeding with any plant is always the old saying “right plant, right place.” Most of us don’t live in climates anything like what lavender is used to–but we can help it along quite a bit with some easy tricks.
First of all, to get it through winter as a house plant, choose the right variety. I don’t know the names of either of these for sure, but I am guessing the one on the right is french lavender (lavendula dentata). It’s not a hardy one for me. I am guessing this based on the “leaf” shape.
It tends to say nice and compact in the pot indoors because it is a tropical lavender in my zone. But don’t attempt to plant it outdoors unless you are in a zone 8 climate.
The one on the left? No guesses. It was originally bought as a nice little “Christmas tree” shaped plant in December. You can see it’s very happy because it’s no longer shaped like anything but a mop. The instructions say to prune it hard to keep its shape but I do no pruning on plants in the winter. Once it gets a little more temperate–maybe mid-March–I may take the shears to it. Right now I call it “Cousin It.”
But what’s keeping both these lavenders healthy and mildew free in my house in the winter is just the bare minimum of watering and a south window. They’ll go outside for their “summer vacation,” of course, perhaps as early as April depending on what temperatures do here. After that, we’ll see how they fare–particularly “Cousin It.”