I have ES hydrangeas and I think yours look pretty good. The buds and leaves are still young give them more time to grow and fill out. I wouldn't fertilize again and risk the chance of damaging the plants.

Hello, Jim. They definitely look normal from a bloomage standpopint! No need to worry about that.

My first thought when reading your message was iron chlorosis but your pictures clearly show that the veins are not dark green but light greenish.

Then I observed that the leaves in direct contact with the sun are a lighter shade of green than those leaves in the interior. It is hard to tell if that is caused by shade in the picture or not but, it made me think of sunscorch.

When the leaves in direct contact with the sun get too much sun, they turn a lighter green and eventually look all yellowish (including the leaf veins). Down here in Texas, I provide shade starting around 11am to 12pm to prevent that. But I once had a storm damage a tree that provided shade to the leaves and had to dream a contramption to give them shade.

I would not use the fertilizer for this problem. Generally speaking, fertilizer applications on stressed plants are not recommended. Besides, hydrangeas are not heavy feeders. In the northern half of the country, you can do with one application in June (I am guessing that is where you are located); see the link below. A cup of compost, composted manure or cottonseed meal per application should be enough.

Have you ever had a soil test done? Soil tests can indicate mineral defficiencies that can make the leaves turn yellow and which are not easily diagnosed by us gardeners. For example, nitrogen deficiency can make old leaves turn yellow too.

Luis

Here is a link that might be useful: Fertilzing hydrangeas

You can never have too many buds on ES! You'll notice that almost no 2 bloom heads end up exactly the same because some "branch out" differently than others, making oddly shaped flower clusters. This just adds to the beauty. As a younger plant it may be necessary to put a small green wire fence about 10" high around the base because the mature bloom size + rain will end up making some of them droop to the ground around the front. But if let droop, some even never branches may grow vertically from those, filling in the created spaces.

Once the entire plant has leafed out, shade created by outside leaves may turn the inside ones yellow near the base. As long as there's nice new growth from the base each year I suspect no problems there.