Fill a clean bucket with water. Take it to the garden along with a pair of shears.
Pick clematis flowers as soon as the flower buds begin to open. Cut the stem back to the vine's old wood, which is brown.
Place the cut flowers in the bucket of water. Take the bucket inside. Leave the flowers in the water until the next day.
Fill a flower vase with water. Set it next to the bucket of flowers. Take the cut clematis out of the bucket one by one. Trim each stem to fit in the vase and place the flower in it. The cut blossoms will last for about a week.