Hydrangea stems can be quite pliable but less so in winter. I have read posts about cases where the stems bent or broke due to too much snow but I do not think there is much you can do when it snows a lot.

I always remember someone who, in the Fall, used a winter protection technique that required putting a cardboard on top of the shrub and pressing down until the stems were flat on the ground. The stems did not break (I thought they were going to) and the stems "bounced back" in the Spring as if nothing had been done! Typically though, new stems will bend more easily than older ones.

Here is an larger/older PG tree:

http://agardenforall.com/wp-content/uploads/2012/10/Pee-Gee-Winter-buds.jpg

Here is a Limelight shrub:

http://3.bp.blogspot.com/-0Q4taqYRUC4/UPYxRMYI8uI/AAAAAAAADkk/cioGTHVQvdQ/s1600/GBBD0113-2.jpg

I would be curious to see how your tree does in Spring. Would you mind posting a picture then, if you remember?

I am still in the planning stage of planting a small tree this spring, the H.p. tree is on a short list of 4 or 5 options, each option having its own plusses and minuses. I think I leave the options open until I find an actual specimen that I like :-)

I hope it does not take you as long as it is taking me to choose a smartphone! LOL!!! :o)

:-)

I have a Limelight standard (sorry no pics with me) and so far in its first two winters it hasn't flopped over at all with the heavy snow. It maintains its upright shape like the Limelight shrub Luis linked to. I live in Toronto (z5b).

Note: this is a standard and not a shrub pruned to a tree form. Not sure which you were referring to when talking about a HP "tree".

Just to clarify - a standard or tree form hydrangea IS just a shrub trained into a single stem. Only paniculatas lend themselves to this treatment and they are not grafted (despite the odd comments stating such you may find online). You can either purchase one already trained/pruned in this manner or do it yourself. The outcome will be the same - the process is just sped up and simplified by the wholesale grower.

Gardengal48--around here you can definitely buy hydrangea tree forms which are shrubs grafted to the top of a standard. In fact I don't think I've ever seen a hydrangea standard for sale around here that was NOT grafted.

With the shorter growing seasons here in the northeast these kinds of grafted standards are fairly popular because the shrubs often do not grow large enough fast enough on their own to form a satisfactory standard. It is faster and easier for the growers to graft a young shrub to the top of a standard. So we see the same thing being done not only with Hydrangea Paniculata (usually Limelights) but with small lilacs, roses, and all sorts of other shrubs.

Here's a link to an Ontario grower's top-grafted standards section, and they include multiple hydrangeas. I see these in the local nurseries every year...lots of them.

http://www.jcbakker.com/product-category/topgrafted-standards/

Must be a uniquely Canadian offering, as this is not something seen here. Have never in 30 years of retail and wholesale nursery experience encountered a grafted hydrangea. What are they using for rootstock? I would have concerns about graft incompatibility using anything other than hydrangea rootstock and I can't think of any type of hydrangea which would lend itself to this growth other than paniculata. Then that kind of begs the question of what's the point?

Granted that training one into a tree form is not a fast process under any conditions but it is certainly doable, even in cool, short season climates (I hate to tell you but I am located at a higher latitude than much of Ontario, so a short growing season here as well :-))