I've recently planted out 4 lavender plants and within the first week, they've gone from healthy looking, to dry and withered. I've watered daily, but being a novice gardener, I'm not sure what the issue could be.
Pull them out and soak the rootball in a bucket of water until it stops bubbling. Then replant and pur more water around the rootball so the surrounding soil is wet. If the rootball was dry when you planted it, it will not rewet.