Without a picture hard to tell....

Sorry I tried to down load the photos from my phone.

It lookedlike.they were attached before I posted.

Next time I have access to my computer I will attach the photos.

Measures approximately 3' x 3'

Measures approximately 2' x 2' ; gets more sun and not as protected from winter winds. Zone 5B

The shrubs have different root systems. Both were cut to fit into the plastic pots that they sold them in. But one probably has a more extensive root syste that allowed it to grow more and faster. They both look fine so I would not worry about their sizes. Just keep giving them the same level of TLC.

Luis, would you know what variety they are?

Only that they are H. macrophylla mopheads. Did they not come with a label? Those purchased at plant nurseries have the variety name but the ones sold at florists and grocery stores get a cryptic and useless tag stating only "blue hydrangea", "pink hydrangea", etc. Merrit Supreme is often used but who knows. I do like the shade of blue, don't you? They appear to be happy there.

They were a gift that came from a nursery, but they had no information tag.

We do, the color is beautiful.

Much to my surprise there are "Light of Day" hydrangeas planted 3 years ago to the right and left of the smaller hydrangea.

For the second year in a row the one to the left has a few blooms. We are hoping for better luck this year that the other one will bloom.

No way to truly know how to properly ID. But if they bloom and perform reliably, who really cares?

Logic dictates to not so much guess PPAF named plants in the event they weren't marked. So trademarked or patent-free varieties would be much more likely.

It's a spacing concern is why I am asking the variety. The plant that is doing well is limited to the space it is in.

It would be nice if they always had good tags. I have an unknown lacecap from Lowes that was supposed to be Nikko Blue. I guessed how big it would be and yesterday I was just saying how I miscalculated. Ha! Oh well.