On some levels, I would agree its genes. The old ones I describe, yes, from ground up, they come up big and thick in the same growing season.

The Bloomstruck I'm still scratching my head as while ~many~ stems, it's nowhere as thick as all of the Bloomstrucks I looked in the nursery this year, in smaller sized pots.

The list goes on. I'm just sorta awestruck recognizing that it is no small ~feat to have a new cane comeup fresh, be as thick as it is, all in the same season.

I never did pay much attention to this detail, as due to the fact I am considering removing some of these older ones and thinking will these newer ones ever gain the stamina/size of these older ones, the size of new stems is really a interesting observation.

a1an, u can have strong/ big roots, and stems thick & 5’ without Winter Protection , few to NO blooms they are Macs.. just saying

Hyed The round color blooms do it for me. We have LL in hedge and tree form and while Reliable every year in both blooms and growth, nothing does it more for me than them round colored blooms.

I did identify a new spot along that I am entertaining a row of serrata's

Next year will be interesting. I'm now on year 2 of rejuvination pruning and sofar with this years growth, its promising...Big shout out thx to GG. I actually came across a thread on rejuv. pruning, stumbled upon Houzz Hydrandga forum and GG confirmed my plans on rejuv. pruning.

Hi aian, I thought we were talking about Bloomstruck... Sorry

For the row of serratas, here are some:

http://www.hydrangeasplus.com/category-s/113.htm