Are you planning on using planters? I'm not sure that little strip you have is enough to plant hydrangea.

Hello, thanks for the quick reply. I have 8"x17" openings on the edge of the pavers, as you see in the photo. There is an opening like this every 8 feet. I can dig pretty deep and also make a bowl underneath the ground, if necessary. That would not be enough for hydrangeas?

Another concern: could a mature hydrangea eventually damage the pavers and push them up?

I would not recommend a climbing hydrangea there. They normally have a large root system that will not receive water properly through that 1-2' square opening.

Other species of hydrangea grow shallow, tiny, fibrous roots mostly around the top 4" only so I doubt they will push up the pavers much unless the pavers were already loose. They also need frequent watering and am not sure they will get enough water. Probably enough at first but not long term... as they start to grow under the pavers, they will not get enough moisture. The roots will then be dried out by the pavers during the day. Then at night, the pavers will release heat, just as the hydrangea roots expect some cooling. Not necessarily good conditions for the mopheads.

I think you need to remove a row or two of pavers to give whatever you plant some room to grow and a place for the water to go. Have you considered creeping fig (ficus pumila)? It tolerates shade and would give you the thick coverage that you are looking for.

I have had no luck with climbing hydrangeas in shade and I agree an evergreen climber would be a better choice

I have had some really nice climbing types of euonymous here on the East Coast. It requires NO maintenance. Wonder if that would thrive there?

While they need some sun or bright light to bloom well, climbing hydrangeas - all species - ARE shade lovers. But they are also slow to establish, slow to flower and will not bloom profusely in very heavy shade.

The OP's situation is not very heavy or dense shade. One of the climbing hydrangeas selections would work well. But I'd still lean towards one of the evergreen choices :-)

@luis_pr you wrote:

"Other species of hydrangea grow shallow, tiny, fibrous roots mostly around the top 4" only so I doubt they will push up the pavers much unless the pavers were already loose. They also need frequent watering and am not sure they will get enough water.Probably enough at first but not long term... as they start to grow under the pavers, they will not get enough moisture. The roots will then be dried out by the pavers during the day. Then at night, the pavers will release heat, just as the hydrangea roots expect some cooling. Not necessarily good conditions for the mopheads."

Your prediction of what happens when they start growing under pavers and not get enough water - is interesting and sounds logical. I wonder if this is why I have trouble with some jasmins I have planted along these same pavers. Their opening is also 18"x8". I lost one last year after it lived 3 yrs and now I'm losing another one. It looks like it is dying from thirst even though It's getting drip irrigation water every day. Could the cause be the scenario you describe? There are still 4 other jasmins planted the same way (in little openings in pavers) that seem to be doing well.

Yes, it could be. Try removing some pavers. It may help.

Hello @gardengal48 (PNW Z8/9) and @luis_pr,

I just realized that although the spaces in the pavers are tiny (18"x8") there are no pavers behind the pavers in the neighbors yard. See photo below. A couple of feet away in his yard are pretty established privets.

That solves the space problem for evergreen hydrangeas? My assumption is that hydrangea would run roots into neighbor's.

My other question: would it flower? Remember it's in shade almost all the time.

I'm not sure if you realize just how big climbing hydrangea gets. It will consume the entire fence, and branch out into your neighbors yard. The vines are thick and you can't weave them through the fence like you can a clematis.

You are the only person I know of that would have it growing in California's bright shade so I am not sure how it will do for you. Be ready to assist it if it has difficulty climbing the chain link fence.

Half of the root system may end up by your neighbor's and the other half will be on your side. With that distribution, it may still have a hard time getting water on one side during the worst of the summer months. But... if you decide to proceed, report back how is it going so and what you learn.

Any idea how old your neighbor's trees are and how long do those trees live (you are depending on them being there to provide shade after all)?

Hi @luis_pr, are you saying I NEED the neighbor's trees to shade the evergreen hydrangeas? If they go away someday, the sun would be kill the hydrangeas?

@suedonim75 thanks for the response. speaking of Clematis, it sounds like it's what I need for this fence, but is there one that would do well in shade? I read:

"Clematis are happiest with cool shade at their roots and warm sun on their foliage. "

In the hottest part of the summer months, you would need the shade to protect the leaves. The leaves will fry easily in temps above 95F. I have seen two petiolaris fry in the PNW and in New York when they have too much sun.

"I have seen two petiolaris fry in the PNW and in New York when they have too much sun."

Hmmm....can't speak for New York but I see plenty of climbing hydrangeas in full sun here without issue. Including the one I inherited with my current garden!! However the PNW is not LA and it will be significantly hotter and drier in that location so a more tropically adapted vine would be a better choice - bougainvillea, thunbergia, passion flower, pandorea, distictus, mandevilla, snail vine, etc. A visit to a better local independent garden center should turn up countless possibilities.

I think you're in Washington but this was south of you (in Oregon, south of Portland). Normal PNW temps are ok there for a CH until you get to hot temps in full sun in the summer months or extreme ones.