If sun is the only concern and you are talking about slightly less sun but say 2 or more hrs, you may be fine. Hydrangeas require s-o-m-e sun to perform at their best but even with 2 hours of sun, or with dappled sun or even in full but bright shade, they will still produce blooms. It is only when they are in dense shade that bloom production goes down a lot.If you like ES and have had no trouble with it, consider adding more. Multiple ESs probably would "look better organized" than if you had different mopheads varieties along the wall.

If you want to use something other than ES, you can try the Bloomstruck Hydrangea (new to the Endless Summer Series). Rebloomers in the Together & Ever Series, Let's Dance Series, etc are also a possibility.

You could order by mail or select from local plant nurseries. Maybe visit nearby Nantucket Hydrangea too!

Glyn Church recommends these non-rebloomers for shade: Immaculata, Marecal Foch, Mme. Travouillon, Parzifal, Quadricolor and Sister Theresa.

Thanks!

Unfortunately, since you are zone 5, you will want to get a variety like ES that blooms on new wood as well as old. That is probably as important as shade tolerance, since in cold years in zone 5, a big leaf hydrangea that only blooms in spring may not bloom at all if the buds are killed. So check zone hardiness and potential for rebloom when deciding which variety.

Hi there... I am in southern Maine on the coast (zone 5b). Endless summer hydrangeas are a terrible idea for you. In zone 5 they will have a couple scraggly blooms, even in sun.

i have an Endless Summer (macrophyla) blushing bride in part sun. It always has a few pathetic blooms around the base of the shrub that originate from the old wood that was not killed below the snow. A bloom on the top of the bush is rare, and looks lame by itself. Most of my neighbors have macrophylas that also do not perform.

I recommend the hydrangea arborescens cultivars. People will tell you they don't like invincibelle spirit because it isn't as showy as other hydrangeas. They are right... But it blooms better in shade than any other hydrangea I have grown in my yard, and I really like it. I have not grown Bella Anna, but it is supposedly good in shade as well. Annabelle does great in zone 5, but I have not tried full shade with it. Strawberry vanilla blooms well in part shade for me, but it is very floppy and leggy. I am going to try harder pruning for it.

There are also a few lace cap macrophylas rated for shade. I have not dared try them because they are macrophylas. (Blue billow, blue wave). I have heard one person say pinkie winkie worked for them up here. The climbers are supposedly shade tolerant, but be sure you have a very strong support!

Good luck!

I was only considering H. macrophylla, but there are several other kinds of Hydrangeas that are hardier for our area. If you are going to consider all kinds of Hydrangeas, we would need to know more information in order to know what to suggest.

How much sun does the area actually get, and is the shade dense or bright or dappled?

How important is the bloom color to you? That is, does it need to be blue like ES is in New England, or are you fine with pink, lime or cream to white?

What are your size requirements? Do you have room and something like a large tree's trunk to accommodate a 30' vine? Will it be in a bed (island, foundation, border, or perimeter), and if so, is there are general height and width range that will fit well?

In addition to the H. macrophylla (big leaf hydrangea) and the similar H. serrata (mountain hydrangea) there are two other shrub species, H. paniculata (panicle hydrangea) and H. arborescens (smooth hydrangea). There are also a couple of species of quite large vines (H. anomala petiolaris and Schizophragma hydrangeoides).