If it makes a difference, here’s a picture of the parent plant. I’m still not sure the variety. It was here when we moved in 2 years ago. It does have some old woody looking stalks (with no leaves just kind of dead). But it is mostly green stems and leaves. The flowers are blue or blue and white mixed. I admit I have done nothing at all to prune this plant in previous years, mostly because I was worried about doing it wrong. This year it is blooming most, which surprised me because there is a large tree above it which is shading it way more this year than previous years.

I would not separate them yet. Nor should you wiggle them. 3 weeks is a short time for cuttings and they probably don't have much in the way if roots, if any. Green tops, and even new leaves, don't mean there are roots yet. I'm not familiar with your winters but I think your best bet would be to bury the pots in the ground in a sheltered spot and mulch well. Then forget about them until the spring.

Your Hydrangea is a macrophylla so it might not be performing at its best in your climate. They flower on old wood, so, if that gets frosted, you get a much reduced flowering on new season's growth. Don't prune it other than dead heading and removing stems which are definitely dead after the winter.

Phew, thanks! I will stop wiggling and leave them alone awhile longer then try to bury them for the winter.

That’s so helpful to know about this particular variety potentially not doing well in this climate. It has had only around 4 flowers this year. I attributed that to my lack of care but maybe it is not happy because of where we are.

Thanks so much for your help!

if you took the cuttings from well established long term plants.. one would think that they are fully zone proper for your area...

treating them like some foo foo zone pushing plant is not the way to go...

imo.. do not mess with the attached garage...

just HEAL THEM in... and let ma nature do what she will with them... they should be fully able to handle winter...

to me.. it seems like you started this a bit late.. and if you fail.. do the research to find the proper timing .. so that when you do it again next year.. you will have success ...

you probably should have started in mid to late spring.. not the middle of august... but i could be wrong about that...

watch a bunch of these for the next time you try...

ken

https://duckduckgo.com/?q=Hydrangea+macrophylla+propagation&t=ftsa&iax=videos&ia=videos

" if you took the cuttings from well established long term plants.. one would think that they are fully zone proper for your area... "

And with Hydrangea macrophylla, that would be an invalid assumption. While they may be root hardy in lower zones, they tend to act as dieback perennials and given their blooming requirements, often fail to produce flowers or do so sparingly and very late in the season.

Hydrangeas are very easy to strike from cuttings and as long as the shrub is still showing green leaves, it is not too late to do so. But given that the cuttings are not yet established, they cannot be expected to survive winter conditions in an unfavorable climate without care and a degree of protection. I would not recommend heeling them in (note spelling - not healing!!) The basement is too warm but the unheated garage should be just about right but I'd watch for any predicted extreme cold snaps and try to maintain the temp at freezing or slightly higher.

btw, once the cuttings have lost their leaves and gone dormant, light in winter is not a requirement. Just do not allow them to dry out completely.

Sorry to be contrary, but everything in the previous post (ie Ken's) is innaccurate.

Hydrangea macrophylla is not necessarily zone appropriate for the OP. In zone 5 H. macrophylla is a foo foo, zone pushing plant. Because they flower on the previous season's wood, they do not flower as they should in places with cold winters. The stems which would bear the blooms get frosted to the ground. The plant itself will put out new growth but that will not necessarily produce any, or few, flowers. Note the solitary bloom in the OP's picture. In a better climate every stem would have a flower. Like this one in my garden:

Photo taken before the blooms were fully open. They are currently the size of a baby's head and the foliage is hardly visible.

Furthermore, late Summer is exactly the right time to take Hydrangea cuttings from new wood.

And it is hEEling in, not healing, because you use your heel to firm the plant into the ground.

" Sorry to be contrary, but everything in the previous post is innaccurate. "

LOL!! I trust you meant ken's post and not mine, as we pretty much agreed on all the inaccuracies posted :-))

Let me say again that a zone 5 location is NOT conducive to the successful growing of Hydrangea macrophylla, even those newer varieties bred to flower on current season's growth as well as old growth.

Yup. You sneaked your response in while my post was making its ponderous way across the Atlantic.