all I can say is that this is very weird.

Can you post a picture of what does it look now?

I'll work on a photo. Ironically I'm the same lady who can't get my Annabelle hydrangea to stop taking over another flower bed, even though it seemed it was completely dug out.

It sounds to me like the plant - assuming it WAS accurately labeled - has an inadequate support system. Climbing hydrangeas do not really grow well on trellises. Their climbing structures - aerial rootlets produced along the stems or 'holdfasts' - need a larger but rough expanse to adhere to than most trellises offer. Something like a brick chimney, a solid fence, wooden shed, or large tree trunk, rather than the 1x1 supports common to most trellising.

You are also borderline for the hardiness of this plant and that may very well be affecting both its size and its ability to flower. These plants need to achieve both some physical maturity as well as height before they bloom freely.

Thanks for the input. It's really good to hear from other gardeners.

There is no doubt it is a climbing hydrangea and was labelled correctly, but I appreciate that thought.

The zone thing is interesting, and frankly I never thought of that. It doesn't get dieback from the winter though (unlike my magnolia and other things that are a little out of zone) and gets a snowcover that covers all the height to date.

The trellis that has been behind it for the hydrangea's life - likely more like 15 years, was not purchased trellis but a rough one my husband made out of hand cut 1x3 inch pieces. Now, the pieces were spaced 8-10 inches apart so perhaps this is part of the problem, not enough surface area to "grip". Just a few months ago this trellis had to come down for repairs on the shed, but there wer very few little aerial rootlets clinging anyway - only the largest of the about 20 different stems coming up from the base seemed to have any.

Unfortunately the shed is siding, and I don't have another place to relocate the climbing hydrangea, so I guess what I need is some sort of solid fence like trellis with slats closer together.

Any suggestions on fertilizing/soil amendements?

What is your soil like as far as texture, moisture, pH and fertility? What kind of sun does it get? Is it mulched? It sounds like something it needs isn't being provided. I agree with GG48's suggestion of a broad and textured surface to climb. Make sure whatever you provide is sturdy - these can be huge, weighty plants.

I have a couple of these, one in about 5 hours of sun and one in full shade that is younger and variegated. My older one took about 5 years or so to start growing well and another couple of years before I saw blooms. It climbs a concrete retaining wall and doesn't grow well above the top of the wall. My younger one is only on its second season and is still not much larger than when planted. It will be growing up the trunk of an oak when it gets going.

I found this thread because I was wondering how fast these hydrangeas climb. We just planted one that's about 4-5 feet tall. It will be part sun and is located next to our brick chimney.

I want to encourage it to climb, climb, climb.

Oh, and bloom, too!

Encourage all you can, but you won't see a bloom on wood less than 3 years old, transplanting sets blooming wood back a year, and usually it is several years before it has a growth spurt.

This is a plant that tests a gardeners mettle and brings a painful lesson in patience. (And feeding and fertilizing will not speed things up.)

The 1x3 inch boards are plenty big for your rootlets to attach. If your new growth is laying on the ground, continue to tie it up until if attaches its self. Al