Cherry Laurel Hedging

I planted a Cherry Laurel hedge last November. The original soil was full of clay & debris, so I dug the trenches out, and filled with a good quality top soil, mixed with some well rotted horse manure. I have ensured the plants were watered each evening, during the dry weather. Much of the hedging now appears to be dying. Any advice on how to save the plants, if at all possible, would be very much appreciated.