Not sure why some of the leaves are turning yellow here are a couple pictures can anyone suggest ideas to help.

Looks fine to me. It's probably just losing older leaves.
You could give it a feeding of Epsom salts, as per directions on bag. Epsom salt is not a salt per-say. It won't hurt the soil.
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Philipwonel said:Looks fine to me. It's probably just losing older leaves.
You could give it a feeding of Epsom salts, as per directions on bag. Epsom salt is not a salt per-say. It won't hurt the soil.
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Sorry, Philip, but Epsom salts (magnesium sulfate) actually are a salt per se.

If the problem was magnesium deficiency the veins on the leaves would still be green while the rest of the leaf was paler. That does not appear to be the case on this plant. If it is a nutrient deficiency, since it is all over including the veins, and on the older leaves, it more likely would be nitrogen. But it could also be lack of water and various other things.

Has the plant been fertilized at all?

I will fertilize it sooner I'm not sure.

Sorry Sue. After getting hammered many times, for telling people to try epsom salts, which by the way I've been told to do over 40 years !!!
I researched it a couple years ago.

It seams the pro-epsom salt people don't want to argue with the nay-sayers.

The epsom salts, releases certain unavailable elements to the plant.
Or ? Did you read that far ???

Ta. Ta.
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Philip, this "unavailable element" is magnesium - because Epsom salts is magnesium sulfate, a salt. I'll quote "Magnesium sulfate is an inorganic salt with the formula MgSO4(H2O)x where 0≤x≤7. It is often encountered as the heptahydrate sulfate mineral epsomite (MgSO4·7H2O), commonly called Epsom salt. ". From: https://en.wikipedia.org/wiki/...

It can be appropriate to use Epsom salts. It can also be inappropriate to use Epsom salts. There is no one size fits all. Just because it works for you does not mean it won't cause a problem for someone else. The symptoms on the hydrangea do not suggest magnesium deficiency.

Yes I did read that far but I don't think you've read any of the references I've given you or you would understand why it's wrong to suggest applying magnesium unless it is actually needed. It occurs naturally in soil, you only need it if there isn't enough in the soil.

We'll just agree ! To disagree !

Thanks everyone