I would over-winter them in an unheated garage or storage shed. Make sure they are watered well before storage, and as the days start getting longer in the late winter, check the moisture level of the soil (I usually pack snow on the pots, that way when the thaw starts, the melting snow slowly and thoroughly waters the pots). I've been over-wintering in the garage for years with no problems.

I have successfully overwintered hydrangeas in a slightly heated garage (we keep it at about 45 degrees). I would pot them into slightly larger containers than what they came in.

Hydrangeas aren't especially happy as houseplants, at least not in most of our households. Indoor (low) humidity and inadequate lighting aren't likely to encourage the kind of growth you imagine.

A semi-protected location where they will be allowed to go winter dormant may work better for you if you prefer not to plant until Spring.

Bring them inside as soon as they go dormant. Once that happens, the only growth that you can get will be in the roots. Of course, due to this microclimate, the shrubs may not have any winter dieback this winter (but they may in some winters once you plant them in the ground). Water them once every week or once every two weeks.

mollydog, I have a few small cuttings that I brought inside the bay window already, because we are getting frosts now. One of them continues to have bright green leaves while the others are 'brown edging' already.

For those who take them inside a garage or shed; is this a frost free environment for you? In my unheated out buildings we could freeze solid for a couple of months.

Is it a possible better location in a 'root cellar' after dormancy? No light down there, of course.

The pots usually freeze. This will not harm the bushes as long as whatever you're storing for the winter is hardy in those temps. Think about what happens to hardy plants in the ground - same thing. I pull plants in the garage when they are dormant, and the pots usually freeze and stay frozen until temps warm in the spring, same as outside. I normally leave a large whiskey barrel with a Rodgersia in it on my patio over winter (I can't drag it up the steps, the patio is sunken), I just push it against the house and barricade it with bags of leaves. Been doing it for years and it's still going strong.

These are a cultivar of Hydrangea arborescens, for heaven's sake -- the hardiest of all the hydrangea species! Unless you live in tundra, these can (and should) be planted outdoors, even now and even quite young plants. If a very small size, pot 'em up and sink the pots in the ground. Mulch the top with fallen leaves or straw and you're good to go.

Hydrangeas are not houseplants. As Mor stated, conditions indoors are just not conducive to long term care and viability. And being held at temperatures that differ very much from normal outdoor winter temps can alter the dormancy period.......either preventing it from happening or significantly shortening it. Neither is desirable and places unnecessary stress on very young plants. Remember that you will get the best performance from your plants if you provide them with their optimum growing conditions. Encouraging a plant to push 'extra growth' during the time of year it is not typically in growth mode is not a great idea.

Now I saw a garden show and they said to be sure and use clay pots because the plastic ones won't breathe. However I think the clay pots might crack, even if placed in the ground.

Mollydog, are you going to try one in the house to see how it goes?

Re: Clay pots. There are pros and cons.

It is true that clay (or any natural material) is better for root growth than plastic. The hot sun hitting plastic pots can fry roots, but obviously not a problem if pots are in a shady area. The flip side is plastic retains moisture better than clay.

Clay pots pull moisture from the roots, and clay pots dry out very rapidly, so have to water more often (and have to water REALLY often in hot and/or windy weather). This can be circumvented by lining the interior of the pots with plastic, but then you're losing the benefits of the natural material (more oxygen to roots, cooling of the root mass).

I personally prefer natural materials - I just hate the look of plastic anything, and in my experience, plants overall grow better when planted in natural materials.

In many of my large decorative pieces, I plant the plants inside a plastic nursery pot, and plop that pot inside the pottery (can't even really see the inner pot once they're inside the pottery). I do this because many of my pieces are too big to actually fill with dirt, and because the clay isn't in actual contact with soil, there is less chance of cracking from moisture over time, and it cuts down on watering. At the end of the season, I just pull the plastic pots out of the pottery and do whatever I need to do with the plant material, and store the pottery for the winter. Yes, I'm losing the benefits of the clay, but it's just easier this way. In my smaller pieces, I plant directly in them.

Clay/cement WILL crack if left outside over winter or if stored in a dry location but filled with moist dirt, so if you don't have a place to store it, you don't want clay, and you do have to "clean up" at the end of the season. The thicker and better quality the clay, the pricier the piece and the less chance of cracking, but still have to take care of it.

I have decided to drop the plant, in its original plastic container, into a well drained hole and mulch heavily. Thanks for the ideas that the other options can be successful.
[The OP abandoned this thread too early.]

A couple of reasons why I don't just plant it are, number 1, I want the sulfur to settle in for a season because I put it on pretty thick. Number 2 I want to observe how quickly the roots fill in the other half of the pot. I'm thinking about checking Memorial weekend and permanently planting it then.

Leaving pots above ground is riskier the colder the zone gets. The temperatures of roots freezing in an above ground pot is not the same as roots freezing in the ground.

I have 3 hydrangea cuttings that are only 3-4 inches high. What's the best method to winter them over? I was going to put them in a window well that gets afternoon sun. Any suggestions would be appreciated.
Thanks!

Jetlag, are the cuttings rooted or just recently taken? Your question can't really be answered without knowing your zone. Here, I'd leave them outdoors exposed to the weather, only move them some place semi-protected or under a dense evergreen if a dry hard freeze was predicted.

My first group of cuttings died. The ones I just started a month ago are doing well but just starting to put on a tiny bit of growth. I am trying to decide if they should go under the house or up in the attic in front of a window or keep them in the unheated plastic greenhouse.

Madeyna, the suggestions you get could be different depending on your zone. Same advice wouldn't be true of Z4 as would be for Z9...Why not go to My Page and add your Zone to avoid confusion.

I cann,t load my page without errors in it. I,m a zone 8 (above Longview Wa.)but probly more like a 7 because of living up high and in area the gets hit hard with Columbia river winds.

Madyeyna, my mother is in Longview, I was born there :)

You could use your plastic greenhouse (watching to make sure your pots don't become dry), or your cuttings should be fine outdoors for most of winter - the roots will continue to develop in chilly wet temperatures. If there is a winter storm predicted with temps in the low 20's, teens (something like we had last Dec), you could move them temporarily to your garage or the space you mentioned under your house if convenient, an unheated porch....don't bring them inside your warm house, and put them back out when the weather moderates.

I successfully overwinter smaller plants on my front porch, which is heated, but faces west, so can get down to 45 or so on colder days. They usually go dormant and drop their leaves, but will bud out again. Just keep them well-watered. What I liked about them is they bloom in about April - a lot earlier than normal.