Within reason, they can be pruned to kept a bit smaller. What size of a plant do you want? Between Firelight Tidbit, Little Hottie and the ones you mentioned there nice choices in that 3-4' range and don't require pruning. In fact, I find these compact more mounded types look worse with a hard dormant prune. I just prune in spring to remove the previous years flowers if they don't fall off over the winter. Paniculatas will tolerate full sun, but the flowers are more likely to brown out if planted in dry spots. I live on sand so I put them in spots with some light shade.

If you think the Bella Anna is worth moving (I threw mine out a few years ago because it was a floppy disaster), cut it back by half and go for it.

"can be pruned to keep them smaller" - yes but do you want to add another yearly chore to your spring to-do list? It would be best to choose a variety that can attain its size at maturity in the location that it is planted instead. If you prune paniculatas often, they may end up flopping a lot. Also, some paniculatas can be very vigorous and will reclaim a lot of their lost height in just one growing season.

You can move Bella Anna but I would wait until the plant has gone dormant.

I grow several Endless Summer Original Hydrangeas in the ground, but this was my first year growing them in pots. Will I need to bring them in the garage over winter, like I do potted roses, or are they safe to stay outside? The pots are 18", and made of a plastic material. The ones in the ground die to the ground every year, then grow back larger in the spring and bloom on new growth.

You need to bring them in somewhere that stays cold but above freezing. A garage perhaps? The alternative is to dig a hole large enough to accommodate the container and heel them in for the winter, mulching well. But you will still have that old growth dieback, just as if they were planted in the ground.

Honestly, very few shrubs of any kind will survive a zone 5 winter in a container outdoors without some sort of protection.

Thank you, gardengal. That's what I expected, but didn't know for sure. I'll bring them to the garage when I bring in the potted roses.

rouge21, that photo of your Bobo is amazing! I love how lush and full they are, and yet compact. Also, I really love seeing how you use the different companion perennials and the combination is just wonderful! What is that tall, airy, purple plant please? Is that a verbena please? I bet you it is one of those pretty things that I cannot grow in zone 3/4!!!!!!!! :-(

waynez5, I agree with others that it is really preferable to not to have to prune your paniculata. Also, since you are in zone 5, don't expect the mature size of your paniculata hydrangeas to be the same as those planted in zone 7. They will probably be smaller than advertised For instance, I used to live in Zone 5, and my Quick Fire there never really reached the large size that others observed in warmer zones. Now that I am in zone 3/4, my Quick Fire size is smaller again! So you may want to take that into consideration. Good luck!

You are very kind @ostrich :).

What is that tall, airy, purple plant please? Is that a verbena please? I bet you it is one of those pretty things that I cannot grow in zone 3/4!!!!!!!!

If you are referring to the tall flowered plants on the right side of the picture, you for sure can grow it in your zone 3/4! It is the self seeding annual verbena bonariensis. I love this plant (as do butterfles :)).

Thanks, rouge21!!! Aha! So it is an ANNUAL verbena that self-seeds.... I guess I can grow it here :-) Thanks!

It is actually a perennial but a rather tender one....only to zone 7, But self seeds so freely it can be easily grown as an annual in colder zones and still return the following year. Unfortunately, this habit makes it a borderline invasive species here in the PNW.

rouge21_gw (CDN Z6a), I am in rural Burlington, ON and have never been able to find verbena bonariensis to purchase. Can you please share where you've bought yours?

@lowville5 zone5b/6 ON, Canada, Verbena bonariensis is almost always sold as seed in my area.

@waynez5_ia, IME an established panicled hydrangea will regrow about to its prepruning size within one growing season, so to my mind it makes sense to buy one that will stay in your desired size range rather than teying to control size via pruning. This will have the added advantage that older branches are more stiff and so less likely to flop with heavy blooms or adverse weather. Plus I prefer to spend gardening time doing things other than pruning. I have not found that in my site on the northern edge of zone 5 that my panicled hydrangeas are smaller than ezpected. For instance my Quickfire is something over 8’.

NHBabs, your Quick Fire really loved the location! I was never able to achieve the advertised size for my Quick Fire in Zone 5 before, but I have to say that I was happy for it to be compact! :-) The only "giant" that I had was Limelight - that thing surely grew to be about 7 foot tall in my Zone 5 yard then! But the Quick Fire stayed around 5 foot tall or so....

I find here in southern MN panicle hydrangeas grow as large as advertised, if not larger eventually. I suspect there might be other climatic factors that could affect growth potential as you move east to west across the continent while staying in the same USDA hardiness zone. All the USDA hardiness zone tells you it those locations have one thing in common, the average yearly winter minimum temperature in a range.

I'm lucky have a good IGC near me that sells a lot of those tall 'annuals' in jumbo 6 packs that are great for stuffing in the perennials for added color especially late in the season: Verbena bonariensis, tall marigold types, tall nicotianas etc.

I am in rural Burlington, ON and have never been able to find verbena bonariensis to purchase

I apologize @lowville5 zone5b/6 ON, Canada as I didnt see your Q for me till now :(. I bought my "original" VBs as plants from a nursery. I agree it isnt a standard offering at a nursery but it isnt unusual either. But after that first year, as long as those first VBs flower and produce seeds you can have VBs "forever".

Wonderful, thank you rouge21_gw (CDN Z6a). I did buy seed to try, but I read they can be tricky.

(I have never bought VB seeds but as mentioned they grow very easily "in the wild".)