Yes, the roots in containers are more vulnerable to both hot and freezing. They are not nestled in a blanket of the earth. Plants like roses should be placed in an unheated garage or garden shed. Those that remain outside can be burrowed in the ground and heavily mulched. It's also better to keep them in a warmer exposure, such as SE or SW and in a spot sheltered from the wind.

I have climbing roses and jasmine in huge unmovable containers that have made it through the winter for years without any problems. Standard roses I always bring into the shed.

Thanks! One more question...what about cold weather annuals like pansys. Will they survive a freeze in a pot? The ones that I have are slightly protected, they are out the front door under an small covered area.
Carolyne

They will survive a freeze, but not for an extended period of time. The winter annuals need available water to keep their cells turgid and filled with the 'plant anti-freeze' that the hardy plants manufacture. If the soil is frozen solid for days on end, the plants will die. Keep a common sense eye on the local weather so that you can protect (and water) your plants before, during, and after severe weather.

I keep a bunch of plants in my shade house which is on the north side of the garage so doesn't get much sun and have had most of the hardy plants survive in pots. I had clematis in 6" pots and bunches of black-eyed susans, rubeckia, different perennials that I had started from seed all keep over the winter. Some were still in the 6 packs even. Now marginal plants I do take inside or this year I am going to try the garage - it is detached but the doors face south and get a great sunny winter exposure - I am hoping to keep Boston fern, mandavilla and caladiums in pots over the winter in there.

Carolyne, don't shy away from pansies and violas in pots. If they are in a location that gets daily sun, you will have no problem. I have never lost any in pots in North Carolina, 7A and I have tons of varied containers, all sizes in many different locations, but all with ample sun for part of the day.

Plants, such as perennials and roses that are dormant are just the opposite. You do not want them thawing and refreezing. That is what kills them. That's why you use mulch and coverings, not to keep them "warm," but to prevent thawing. But these hardy little buggers will freeze stiff and then on a sunny morning, be tossing those faces around as if it were May!

the rule of thumb I hope to be true is if the plant is listed as hardy at least a zone or two colder than I am, it should be somewhat safe overwintering outside in a pot, but last winter, several plants that were supposedly hardy to zone 5 didn't make it through the winter in their pots, while some I don't think were quite that hardy (like the hot lips sage) did (and they were all in the same part of the yard, got treated the same)... I'm hoping to get my fall planting done over the next few days, assuming whatever that flu shot gave me 10 days ago is actually finally clearing up (probably should have seen the doctor).

If it's something you got for fall planting and you're just not sure if you're going to get to it, if it's cheap and you thihnk it might make it, try putting the pots close to the house, where it will hold warmth and shelter them from the wind...

If you have a lot of money invested, you might bring them in, but bear in mind I brought in 5 plants last winter, as well, and killed them just as handily with no water or light.

Best guess, I think, lol.
Jeff

I just read in a newsletter from a college horticultural program that nurserymen start to worry about potted plants at 15 degrees fahrenheit and below.

Somehow i think there would be a big difference between perennials and woody ornamentals, which would seem tougher.

Thanks everyone!! I've brought my tropicals and etc. in, and I plan on putting more pansys in pots by my front door. I have one more question for you...I have some pots (with pansys) on stands and in window boxes. If it freezes do I need to put the pots on the ground to protect them? Ya know, to keep the cold air from going under them too...seems like that might freeze the roots easier. Thanks!
Carolyne
P.S. In case you haven't noticed, I think this winter's going to be a very cold one!!

Pansies are very tough. Again, the key to their survival is being in the sun for a little bit each day. The more the better...they like that unthawing thing that will kill perennials. Pansies on a covered porch on the north (like mine) would not survive, I don't think.

Btw, pansies in window boxes sounds so charming!

I have 4 window boxes and about 5 different planters with pansies, violas, snapdragons, dianthus and parsley in them and they have no problems lasting all winter. They have all different sun exposure. They do tend to sulk in January but my what a glorious show they put on from late January on. Violas will bloom better than pansies during the cold spells. When I lived up in Delaware the pansies were under snow in pots and still came back once the warm sun starting to hit them in February. They are tough little buggers.

back in the day when i paid a lot less attention to such things, i had a lot of plants survive in pots when temps here got below 15 degrees. azalea, hydrangea and confederate jasmine are some i recall offhand.

and i will attest to the toughness of pansies - i've had them survive after thick coatings of ice, and go on to look beautiful once again. for me, it seems they're a lot less tolerant of our summer heat than any cold we can throw at them.

two-cents posted ...
marsha

Here's a picture of some pansies that Lynne had on her back deck. These were in a pot set inside a planter box. (faces northwest - so little/no sunshine in winter). This was taken last Christmas-time, when we had that ice/snowstorm and the 9 degree nights. I'm not 'plant-smart' like most of you guys, although Lynne's doing her best to teach me the difference between weeds and plants ;) , but I think I've heard before that the snow/ice actually insulates the plants from the frigid air temps.

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Thanks! GReat shot! I love pansys...they're just so cheerful!:)

We had some single number temps last winter, but the viola's in the ground at least didn't mind at all. Blooms were sparse over the winter, but in the spring they were awesome and ready to bloom their heads off.

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Rootdigger those are so cute! I like the dark purple ones especially.