Overwintering Rosemary

My rosemary bush in the sink after its weekly shower.

I may be able to grow plants outdoors, but when it comes to house plants I am a disaster. Every houseplant I have ever tried to grow has died a slow, agonizing death. Or, if it didn't die fast enough, it would end up in the compost pile in an effort to put it out of its misery. So it is something of a miracle that I have been able to keep a rosemary plant alive three winters in a row on my kitchen windowsill. Mind you, it never looks happy after it has been on the window sill a couple of months. If winter were any longer, I'm sure the plant would die in protest. I put it back out in the garden in May, and it always takes a while to perk back up, but so far it always has.

I've read that overwintering rosemary can be tricky, even for those gardeners with a green thumb for indoor plants. Ideally you would overwinter it in a cool room (less then 60 degrees) with good air circulation and lots of light. I don't have room that fits this description. So my rosemary gets to sit in my hot kitchen on an east facing window sill. I think the real trick with rosemary is getting the watering down right. The roots will rot and the plant will die if you over water. The foliage will dry out and fall off and the plant will die if you under water.

I'm guessing that I have somehow managed to come up with the right schedule for watering. Once a week I put the potted plant in the sink and spray the whole plant down with water for several minutes. Then I let it sit in the sink for an hour or so and make sure all the excess water has drained out of the pot. Rosemary really hates wet feet. I've read that using a clay pot will lessen the chance of root rot.

The other major problem I have experienced with rosemary is that when it is brought inside, it gets covered with fluffy white mildew. Many sources recommend using an insecticidal soap on the plant on a regular basis. I've never done that, but when the mildew starts growing, I put in the sink and wash the mildew off with plain water. This seems to work, but has to be done on at least a weekly basis.

I have heard that it is easiest to overwinter young rosemary plants. The older they get the harder they are to keep alive indoors. We will see how my rosemary bush tolerates its fourth winter in my kitchen.