It may resent the mulching. Might keep it too moist. Do you have an unheated, sheltered location to move it to? That might work better.

FataMorgana

No, I don't have a place to easily move it. I'm in an apartment and they won't let me place it under the stairwell, and the storage space is already filled with my other garden stuff.

The pot I'm going to upend over it is large enough that the mulch would only contact a circle of about 5 inches around the pot. I'm just concerned that the pot and maybe a black plastic bag wouldn't be enough to insulate it.

Well, I'm not sure what to tell you. Moisture held around the plant may cause mold and rot. That will not be good for the plant. Rosemary, sage, and others are from a hot and dry Mediterranean climate. What ever you can do to maintain airflow in your coverings may improve the chances of success.

FataMorgana

Thanks, I'll try to take that into consideration. I know there is at least one local lavender farm in the same kind of microclime, and a lavender I grew a few years ago did manage to make it through one winter outdoors in the ground (tho it stayed small and was later stolen), so I am hoping that this rosemary might do the same. I've heard it might not be as hardy as the lavenders were, tho.

But back to my original question...at what point should I cover it? The day before the first freeze? The week before? Right now it seems perfectly happy with the night temps in the 40's (not too much different than our spring and most of summer night temps...).

--GW

Look up your rosemary variety via your favorite search engine to find what is the lowest temperature it can take. Hardy zones also translate to lowest temperatures if you are finding only that data. Then watch the weather reports. Cover before it gets to the temps the plant can't handle. Wait on covering as long as possible for best success.

FataMorgana

Thanks again! I did as you suggested, and Google-fu says that most can handle down to the 20's and even the teens. Since its raining today and tomorrow, I'll wait until Tuesday or Wednesday to see if it dries out enough to cover. Hopefully it will on Tuesday, as that night is the first frost and I figure that would be a good time to cover it up.

I'm fully aware it may not survive the winter at all, but then again it may. We'll see! Seeing what can and cannot survive make gardening in my area interesting!

--GW

Lots of very helpful information. I wonder if anyone is in zone 7(a), north Texas or Oklahoma, and has had success overwintering rosemary in the ground? I lost a plant previously, but am trying one more time with one planted in a raised bed,good soil& drainage,full sun, with some protection from south wind. I plan on a bark mulch, and will provide supplemental water. Any corrections or suggestions?

Some gardeners where I live manage to overwinter the hardiest rosemary variety named "arp." Conditions aren't quite right for me and I've failed 3 times to overwinter it - my limit. But zone 7 should be most doable.

Drainage is key to winter survival for all the Mediterranean herbs like rosemary, sage, etc.

FataMorgana

Looks like it's not an easy plant to overwinter, in or out, most places. I did try 'Arp' one year, but it was one of those years we have here where the winter weather varied from extra warm to sudden freezes, and it didn't work out. Last year I kept this current plant in a pot outside and moved it in when temps got below 32 degrees. That worked, but it was just a pain, so this year I planted it out in spring--now it's about 3 feet high by 3 feet wide, so just too big to manhandle back into a pot. We'll see how it goes, I guess. Thanks for the advice!

I tried overwintering it in our heated (50 degree) garage, in front of a sunny window, but it died. I hate treating rosemary like an annual, but...

If you can find one of those Garden Cloche's that have a vent on the top you can try placing it on top of your rosemary and keeping the vent open. As mentioned rosemary does not like to be kept moist so keeping the vent open will help. If moisture builds up you can remove and wipe dry. The ones I am trying this year have holes that you drive pegs in to hold it close to the ground. I too have not been able to keep rosemary alive over the winter but I have seen one very healthy rosemary in this area that according to the shop owner had been in the ground when they moved in. They had been in the shop for 3 years at that time.

I would use the leaves and perhaps find some more to put around your barrel. You can stuff them inside material wrapped around the barrel starting at the bottom and moving upward. You may want to block the sun from the barrel, to keep the barrel from freezing and thawing.

Rosemary, while it cannot take long and deep freezes, will not die immediately at 32f. It lives outdoors all year round in the UK and can survive moderate frosts for a few days at a time. So I would leave it outside as long as possible before bringing it in. If it died at 50f it wasn't because of the cold. it might have been light or water or lack of air movement leading to fungus, but not cold.

My rosemary suprised me immensely last year. The snow was around 18 inches and lasted for weeks. But come thaw what did I see the rosemary doing just fine. It's still out there and I haven't done a thing except weed around it a couple of times this year. It loves neglect. I wish I could tell you the variety but the nursery just had rosemary written on a plant tag.

Rosemary was an herb that I always would bring into the house and it would DIE sooner rather than later. I started to plant them into the ground in sunny spots with some added sand to the soil to improve drainage. January is normally quite cold and the frost must be deep here but it is also relatively sunny and there are milder periods of above freezing temps (still winters here can be very WET). Now I have hedges of them around the house. Not sure if they are the hardy 'Arps' variety (many were unlabeled from the big chain stores). I thought they would be troubled by last winter's big snow (though it was mild temperature wise)--no problems and they looked great once the snow melted. (And the flowers are gorgeous--they once bloomed in February!) They must gain in hardiness after having been in the ground for several years and increasing in girth.--I do know there seems to be a sharp cut off line in terms of where they are winter hardy--friends one hours drive north or west of my location don't seem to have luck with them. As an added advantage for its use as a shrub, the deer population absolutely avoid these plants--too aromatic! This is probably my single favorite herbs now!

I just discovered this forum; I'm so glad I found you guys!

I'm in Zone 5 (south central Wisconsin). This year I'm going to try overwintering at least one rosemary outside. I have it in a raised bed, not unlike a container garden. My neighbor said she's overwintered it by putting straw on top of it and that's it. It surprised the heck out of me to hear that it was even possible to overwinter rosemary here.

2 years ago, I brought my rosemary inside for the winter, in the sunniest room I have (only 1 or 2 hours of direct sun) and watered it normally. It wasn't thrilled with this situation, but it survived, and in the spring I put it back outside and it did just fine. Did the same the following year with the same success.

So, it's possible to bring Rosemary in, too. Probably mostly depends on whether you have other houseplants you want to protect from outside bugs or have a place to put it.