Why do my rosemary plants die every winter?

January 12, 2008 9:22 PM

Help my rosemary plant live through the winter!

Another winter is passing, another rosemary plant is dying. Every year we grow potted herbs outside, then bring them in before the first frost. Every year my rosemary shrivels and dies right in the middle of January. This year we had a nice, large, 2-foot tall rosemary plant that I was determined to keep alive through the winter. I brought it in and kept it well watered and in a sunny, south-facing window. But now the death has set in--dry, spindly sprigs that look like and unloved Christmas tree.

So what are we doing wrong? Our other plants and herbs are doing well--the parsley is actually growing! If it makes a difference, we live in the St. Louis, where the winters are cold-to-mild and summers hot. But this has happened in warmer as well as cooler climes. Is there some secret to keeping rosemary alive inside during the winter?

posted by slogger to home & garden (15 comments total)

Put it in the ground? Rosemary is about the only thing I can keep alive and with out ever having to do anything to it - it's usually so hearty and maintenance free all year around. I've lived in the northwest and southwest and it has thrived in both places. I've never been able to keep it alive in pots though.
posted by delladlux at 9:32 PM on January 12, 2008

Some suggest that rosemary needs 6-8 hours of full sunlight. During the winter, that may mean keeping a lamp on it after sun down. Others note that it needs good drainage and that over watering can be a problem. Finally, indoor rosemary does best with cool (60F) dry air.
posted by jedicus at 9:33 PM on January 12, 2008

We've tried overwintering rosemary three winters now (in MN, where the light isn't exactly great). The first year it died a death similar to yours in mid-winter, but we persevered. The trick seemed to be having a deep pot that has a lot of space for dirt below the roots and to basically neglect it. By that I mean only water it when the leaves start looking sort of dessicated. Probably not the best strategy, but container gardening in the winter seems to be more art (and a lot of luck) than science anyway.
posted by Helix80 at 9:35 PM on January 12, 2008

I managed to keep a rosemary plant about the same size as yours alive through a couple of Ohio winters by keeping in the ground against a south-facing wall. I mulched it loosely about halfway up the plant. In the summer new growth came out of what looked like dessicated stems. Maybe too late to help you this year, but worth a try for next fall/winter.
posted by memewit at 10:03 PM on January 12, 2008

Rosemary has survived winter outside in NJ for me (in the ground).
posted by caddis at 10:41 PM on January 12, 2008

Rosemaries can be a bit finicky. Here's what has worked for me (I've had indoors-in-the-winters-and-outdoors-in the-summer potted rosemaries for years, and currently have five of them in the house):

Bright light with as much direct sun as possible. I have mine in south-facing windows.
Cool temperature, around 60-62 F.
Good ventilation, but keep away from cold drafts.
Potting mix should be well-drained with perhaps a bit of coarse sand added. Water enough to keep slightly moist. Do not allow them to dry out completely, and never leave the plant sitting in a saucer of overflow water. Their roots are the weak link; if the soil dries out to the point where you're seeing wilting leaves, the roots will die and the plant can't recover.
Some people recommend misting, but I've always had that lead to powdery mildew on the plants indoors, so I avoid that.

Why five, you're wondering? Well, I'm plant-mad, obviously, but I use it a lot in cooking. Also, I lost the six-foot tall rosemary that I had for almost fifteen years to a scale infestation last summer, and I'm trying to train a replacement.
posted by vers at 4:41 AM on January 13, 2008 [1 favorite]

I live in Pennsylvania, and we've got a thriving rosemary plant in our front yard that's been going great throughout the winter. The thing looks like it's at least several years old (we only moved in in August). To top it off, it's on the northwest side of the house, so it's not exactly receiving full sun all day.
posted by Doofus Magoo at 7:24 AM on January 13, 2008

My in-ground rosemary didn't survive the brief cold-blast we had a few weeks ago. I always thought they were supposedly pretty hearty in the cold.
posted by Thorzdad at 7:37 AM on January 13, 2008

I think there are many varieties. The local nursery can probably recommend something that will survive the winters. One particularly severe winter with sub-zero temperatures (rare here in NJ) did kill the rosemary.
posted by caddis at 7:50 AM on January 13, 2008

I brought it in and kept it well watered....

You're trying to nurture it, but... you're drowning it. Try watering it less. Let the top layer of soil dry out. Rosemary is finicky, doesn't like to sit in wet soil.
posted by exphysicist345 at 8:41 AM on January 13, 2008

This is the first year that my rosemary has not dried up and died.

I have it in a basement where all of the heating vents are closed. It is probably in the upper 50s, low 60s in there. And it is actually making new shoots!

I think that the cool temperatures and possibly higher humidity (because the heat's not drying things out) are the key.
posted by Ostara at 8:43 AM on January 13, 2008

Oh, and I've been watering my rosemary once every 2 weeks or so. The soil gets good and dry, and it seems to do okay. During the summer, of course, it uses a whole lot more water.
posted by Ostara at 8:45 AM on January 13, 2008

My rosemary is surviving just fine indoors. I've got it in a quasi-south facing window, but it really doesn't get all that much light. The lavender plant in the same pot and the sage plant next to it were both very unhappy; in particular, the lavender was dying in a similar manner to how you've described your rosemary.

I bought a florescent light, temperature rated to be good for plants, and stuck it a few inches above the plants. I've left that on ~16 hours a day for a week or so, and now I'm seeing re-growth in the lavender and sage plants. So you may want to try that.

I used a GE "bright stick", which is a bulb/fixture all in one, cost me about $30 from the hardware store.
posted by wyzewoman at 9:01 AM on January 13, 2008

I've never had rosemary survive a Minnesota winter, either in or out. I suspect it's colder outside and drier inside here than where you are, though.

But it's great to keep dried--so much better than store-bought in a jar.
posted by gimonca at 10:04 AM on January 13, 2008

You're trying to nurture it, but... you're drowning it. Try watering it less. Let the top layer of soil dry out. Rosemary is finicky, doesn't like to sit in wet soil.

My thoughts exactly, especially since you say your parsley is doing well. Parsley likes far more water than rosemary.
posted by oneirodynia at 1:14 PM on January 13, 2008