Preserving Leaves Liquid glycerin (available at pharmacies) Hot water Vase Leaves Spray paint (optional) Add 1 part liquid glycerin to 2 parts very hot water and mix well. Pour this mixture into a vase. Cut stems of leaves at an angle and place into the vase. Leave them for 2 weeks. The leaves will soak up the glycerin, leaving them preserved, supple and fresh looking. Spray paint leaves if desire.