Who of us actually keeps floral foam around? Well, fewer of us would if we knew how much cut flowers like drinking from potatoes. This is not my idea -it goes back decades- but it works great.
2. Fresh flowers
4. Stick, awl, nail... something that makes a hole
Cut your potato in half. Any shape will do, just as long as the skin (evaporation barrier) is the only part exposed to the air. Think about how you want the arrangement to look and bore the appropriate holes. Take that, potato!