Struggling hydrangea

Hi everyone. I bought some reduced hydrangeas in the hope I could bring them back to life. They have unusual markings on the leaves. Any ideas what this is and how to treat? Thanks

 

Wilting, caused by too little or too much water. Possibly even burnt by the sun.

 

Or, it could be they are going into their winter dormancy so will drop all leaves. I have a couple that look exactly like that

 

I see some fungal leaf spotting but not much. Try never watering the leaves to minimize this problem and discard all plant debris -once dormant- in the trash. The yellowing overall suggests that the plant is (a) starting to get ready to yellow out the leaves in preparation for dormancy, (b) may be getting too much water (use a finger at a depth of 5-10 cm to see if the soil feels wet) or the soil needs garden soil to acidify it (use a soil pH kit to check the soil pH). The blooms also have spots but those are normal as they age. Eventually, the blooms will brown out. You can then either (a) allow them to remain attached for several more months and drop on their own next year or (b) deadhead them (not the same thing as pruning) at any time of your choice. If you plan to keep the plant in the pot, consider bringing the pots into a garage once temperatures start to approach freezing or once the plants go dormant (no sunlight is needed at that point but some watering is still needed). Reduce watering to once a week or once every two weeks (depending on local rains) once they brown out the foliage. No pruning is usually needed; if ever required, do it after they stop opening new blooms in spring 2023; you will then have several weeks, maybe up to a month, before they once again, quickly develop flower buds for spring 2024.

 

Thanks everyone. I got them from the bargains section in B&Q and they were in full sunlight and the pots unusually heavy from watering so that all makes a lot of sense. I will follow your tips and hopefully they will flourish! Much appreciated.