Assuming it's in the ground, not sure what you mean by "not planted very deep" - it should be planted to fractionally below the level of soil in the pot when you first planted it, so if its standing proud above the soil, replant in a deeper hole. The brown on the edge of the leaves could be frost damage - one thing you haven't said is whether it's in a pot or not.

No its in the ground it was not very big and I planted accordingly. t could well be frost damage ,would it have taken to now to show,as it seemed to have survived winter.Incidently do you know if big shrubs do ok in pots.I have a pot 60cm diameter and would love to put some kind of shrub in it to stand on patio.
Thanks for your reply.

Recent frost damage, I meant, as we had a major temperature difference between April and May, with some frost in May too, and that could have nipped new leaves quite easily.
You can put what will be large shrubs in pots, but not for long - they will need transplanting to the garden with a couple of years, and its more the depth of the pot that's important - minimum size 2 feet deep by 12 inches across.

went for a walk this morning and viewed other hydrangeas in my locality and a good number had the same condition.You must be right.Thanks for info on shrubs in pots.My pot is 15 inches deep so think it will have to be bulbs of some kind.Thanks for your help .

My Hydrangea is well and happy and has lots of flowers coming along.It must have been frost damage.I removed the damaged leaves and fed it and watched it carefully .Lovely feeling that it has come through.