What should I mix into the vase of water for fresh cut flowers like roses to keep them a long time?
The best that you can do for extending the life of a rose is to give the stem a fresh cut under water and place in a vase of fresh water. It would be ideal if the fresh cut could be done in the vase of fresh water. Do not use oasis which is a great aid for arranging, but it tends to clog the water transport system up the stem. Additions to the water are now not thought to be necessary. Change the water if it becomes cloudy.