In the ground, many Clems are hardy to zone 4. Not going to be as hardy in a pot though. Do you know what Clematis it is? Some are hardier than others.

Heidi, generally people in colder zones need to plant their clematis sooner than later in the summer to allow it to get established before the harsh winters arrive. If your winters come early and are quite often below zero, I would be tempted to get it in the ground ASAP so it has plenty of time to get established before your brutal winters. I would not wait until August to plant it if that is what you are going to do.

As to whether or not the clematis will survive the winter in its container, it really depends on the specific clematis you have and the size of the pot. Some clematis are more hardy than others and the larger the pot, the larger the soil mass that will protect the plant from freezing solid and not making it through the winter.

If you do decide to overwinter it in its pot, I think it better to move it to some protected place after the plant has been put into dormancy by the cold outside. What you want is a place that will be at or above freezing and not warm enough to cause the plant to break out of its dormancy because growing clematis inside in the winter is a tricky thing to do. Does your garage stay at or just above freezing? If so that would be an ideal place to store it. Just remember that you will have to water the soil periodically so that it doesn't dry out. As for your basement, is it heated or is does it stay relatively cold over the winter? Once again, you want the plant to be dormant before moving it inside and to keep it on the cold side to prevent it breaking out of its dormancy.

The biggest cause of loosing plants in winter is from the plant either being too dry- the water in the soil acts an an insulator, or the soil getting water-logged from rapid snow melt and then freezing again. A pot is more prone to drying out, losing it's protective snow cover too fast and getting very wet. When it does get too damp, the water has no where to go unless it gets warm enough to thaw nearly all the soil in the pot so the water can drain through.

I recently read on a different forum to tip the pot on its side once it completely froze. Store the tipped pot on the north side of something, like a garage. I don't know if this works, but I'd be tempted to try it if I had a potted plant that I didn't mind losing.

One method that works pretty well is to dig a hole and bury the pot, then cover it with a good pile of shredded leaves or mulch. This might not be desirable with a decorative ceramic pot. Plastic would be ok to bury.

I've kept hens and chicks and other sedums alive in the garage, but last year the hens and chicks didn't survive. I haven't tried over-wintering a clematis in the basement, but I have done it with annual geraniums. The key to doing that is the plant must not get light, and keep the soil barely moist. I've kept a white pine (hardy to zone 2) in a pot outside, with no protection and gave it no special attention. It thrived.

I've read in the container forum that people go to great lengths to keep container plants alive during winter. They wrap the potted plant in all sorts of things. They have successes and loses.

I planted a few clematis just before winter and they survived. I know this might make the hair stand up on the backs of some peoples necks, but... what I did was cut them back completely, dug a hole just large enough for the root mass, put the clem in the hole, put soil in any spaces and tamped it around the plant really well to avoid any air pockets, making sure that I didn't leave a depression around the plant for water to collect, then watered carefully. It was lightly snowing that day. They all survived winter.

There is no guarantee that any one of these methods will work. You know how our weather is, there is no way to predict if the winter will be mild, what the snow cover will be, or how deep the frost gets. What survives one year, might not the next.

Let us know what you decide.

Sorry, for a wordy post, I'm sure you probably know a lot of what I posted, but I did a lot of it for our southern friends :-)

Janet, I am surprised you have planted in the fall and not lost clematis. Quite a few others in the northern climes have not had success doing so because they claim the plants don't have enough time to get acclimated and settled and end up croaking over the winter.

I do have a question as to your statement that water is an insulator. That makes no sense to me at all and hope you can expound on that statement. Water has no insulating properties at all. Snow on the other hand is an insulator. Water as it freezes gives off heat known as heat of fusion that can help protect a plant and maybe that is what you were referencing?

I agree that burying pot is another option. The ground, along with any mulch you place over the plant, will act as an insulator and help protect the plant. I too have heard of extreme measures to protect potted plants including wrapping the pot with bubble wrap, putting bales of straw around the pot, etc. I think that if you are going to keep the plant in the pot that would be an option. If the ultimate goal is to plant the clematis in the ground, I would say what not go ahead and do it now.

Overwintering hens and chicks in a basement is far different from overwintering a dormant plant in a pot over the winter. Once dormant, the plant requires little water and provided it is kept cold enough, it won't resprout and try to grow again--a disaster for most people who don't have a greenhouse since the plants get tall and leggy and are prone to aphid infestation.

I've had trouble planting in fall, but the clems were right before winter. (Our winter starts before December 21st - we can't really go by the calendar.) It was sometime around the end of November when I planted the clematis, but I forgot the exact time. Notice I said it was lightly snowing, what I didn't mention was that the plant was dormant, and after that planting day, it didn't warm up enough for the plant to break dormancy.

The hens and chicks were in the garage, not the basement. I'm going to be over wintering my mini evergreens in the garage too. I didn't mind losing the hens and chicks, but I don't want to lose the evergreens.

A pot in the winter can and does dry out. Think of a tray of ice cubes that you don't touch for a long time. Eventually the cubes get smaller and smaller. Even ice evaporates.

The heat that is given off during the freezing of water is short lived and doesn't do any good once the water is completely frozen.

As far as water insulating the roots. Frost will get into dry air pockets in the soil. If the soil is moist, water fills the air pockets, which protects the roots. Maybe insulate was not the precise word to use in that context, but it is close enough :-)

One more thing to avoid any confusion: wrapping pots doesn't prevent the root ball from freezing during our winters, what it does is slow down or prevent the soil from partially thawing and freezing again at night.

If I have said anything obvious, it wasn't meant that I think you are thick, it is only because I had a very intelligent man from California say he was surprised that our plants survived winters. He thought we planted everything again in spring. Obviously, he wasn't a gardener. Since then, I've taken the position that a lot of people who have never lived in a cold climate cannot comprehend how cold it really gets at times during winter.

Thanks for the information Janet. I can't believe the man in California thought that plants wouldn't survive your winters. Was he daft or something!?! LOL I guess he must have thought everything had to be replanted every year or something??

I do know a pot in winter in extremely cold temps will loose moisture--its just that anything will eventually under those cold extremes due to a process called sublimation and not evaporation. That is what happens when the ice cubes tend to go away in your freezer--the solid ice goes to the gas phase without ever going through a liquid phase. That is why even in the olden days before the advent of electricity or dryers people could wash clothes, hang them outside in freezing weather and still have the clothes dry when they were frozen stiff. Sorry about the nerdy science stuff but what do you expect from someone with a chemistry major and biology minor?? LOL

I am still surprised you planted a dormant clematis in early winter when it was snowing and the plant survived. No time for the plant to get established in the soil prior to it freezing solid. Guess the snow provided enough insulation and it stayed suspended in growth doing nothing until spring. Only goes to show what clematis can do!!

I am sure that wrapping pots with anything in your zone won't prevent the pot from freezing. I was merely relating what people in some zones do to protect things in pots that might otherwise die.

The small amount of protection that ice does in soil air pockets is really insignificant for anything in a pot in your zone. Down here, when freezing temps are called for in spring and the farmers want to try and do something to salvage their strawberry crops, they often spray the plants with water to protect the blooms and small fruit by forming an ice cover over the plants. This works only when temps. are forecast to hover right around or slightly below freezing because ice is a good conductor for the cold temps. If it gets much colder than a little below freezing, the crops are still frozen back. That happened this spring around Easter when we got down to 24 or so. The ice provided little to no protect and most of the strawberry crops already flowering or fruting were lost. I can't imagine how cold it gets in your zone so feel that any protection by freezing water is going to be minimal. I love cold weather but your cold weather is probably way to cold for this old southern boy! :o)

Heidi - did you get an answer? It does depend on the hardiness of the variety you chose, but you can plant now -just keep it watered. Many nurseries tell of tossed clematis that sprout out of the compost pile a year later -those roots are pretty tough.

If you decide to keep it in a container, I would pot it on to something larger that will allow the roots to expand, and you can pull into the garage and give more protection its first year.

Because you didn't mention the variety we can't comment on when to prune this plant. You should read up on Types I, II, and III clematis - all have different requirements for when you prune them.

The American Hort Society's Garden Manual has a great section on planting clematis that has proven correct for every kind I have. Not that I'm any great expert but I have several. They recommend planting your clematis about 12-14" deep in a well amended hole. I usually have to use a post hole digger to do this in my clay. Then you slice the bottom off a plastic 1 or 2 liter bottle and bury it small end down near the clematis so you can direct water to the root area. When you water, just water into the plastic bottle and it of course delivers the payload to where it needs to go. I pull mulch up around it and plant something in front anyway to shade the crown of the clematis. You don't see the bottle.

I have also planted clematis in September and October, in fact last year I transplanted a tiny one in the late fall. I gave it a good shot of worm compost juice and its sent out good foliage this summer.

There was a post a while back on this forum about cutting back clematis to encourage root production and I think that is a good idea. For the long term health of the vine, you want a heavy root system.