Fill the container with fresh, cold water and take it out to the hydrangea shrub with you. This will enable you to place the freshly cut stems into the cold water immediately.
Use pruning shears to cut hydrangea stems with blossoms that are fully open and are in pristine condition. Cut the stems so they are 12 to 18 inches long, and cut them at a 45-degree angle.
Remove the leaves from the stems that will be under the water level. Allow the upper leaves to remain on the stems to add greenery to the arrangement.
Place the hydrangea stems into the prepared container. Continue cutting until you have all of the stems you desire for your arrangement.