Convallaria Lily of The Valley has to be conditioned in a different way to other cut flowers:

On receipt, submerge the entire bunch under water for 1 hour in room temperature water.

After, place in the fridge to crisp up for 6 hours before arranging in a vase. Before use in a bridal bouquet - hang upside down in the fridge for the last hour so that all the water is transferred to the flower heads. This will prevent premature wilting.

Learn more about fresh cut Lily of the Valley here.