My mophead hydrangea that I planted 3 week ago is looking terrible. What happened.?

It was fine until 2 days ago. Started to wilt and has not recovered. It is watered regularly and is planted in part shade garden. What do I do
My mophead hydrangea that I planted 3 week ago is looking terrible. What happened.?
Cut back on the watering to once every two or three days, add phosphorus to the soil to give nutrients to the leaves and allumunium to increase the acidity.
Reply:Maybe try some vitamin B1. It could be in shock from being replanted. You should use it whenever you transplants or plants new plants. You mix a very small amount with a lot of water.(the directions are on the bottle). You can buy it any any nursery/garden store.
Reply:Sounds like it's in transplant shock. Don't water it for a couple of days, mix in some osmocote in the top soil before you resume watering. If all else fails, consult a reputable plant house. Check for thrips. they look like little black specks on your flower heads. Good luck!