The 3-R Rule
As soon as you receive your flowers, you should recut 1” of the stems submerged in warm water. You cut the stems to get rid of the blocked Xylem (flower stem), so it can absorb nutrients. Cutting under water ensures it fills up with water right away and does not get blocked by air bubbles. It does not matter if you cut diagonal or straight across; it is a myth that diagonal is better than across and it is scientifically proven.
You should remove leaves that will fall into the water. These leaves have bacteria on them, More >