Fill a bucket halfway with warm water. Pull off any leaves that will be submerged when you place the branches in the water.
Use gardening shears to cut 1/2 inch off the bottom of the branch stems. Cut slits into the bark 1/2 inch up from the end. Lower the branches into the warm water.
Cover the branches with a piece of plastic sheeting. Put the bucket in a warm room for 24 hours.
Cut the end of the branches again, at a 45-degree angle. Fill a tall vase with water and put the branches in the vase.
Change the water in the vase once every other day. When the branches bloom, add floral preservative powder (available at any florist shop) to the water to keep the flowers fresh.