Don't—
Change the water once an arrangement is made but top it up withfresh water each day.
Overlook the value of a charcoal tablet in the water, to keep it pure.
Forget that most leaves should be submerged in water for hours,preferably overnight, to help them retain their firmness
Place wilted roses in cold water. Instead recut and split the stems andthrust into two inches of boiling water and leave until cool. Protectthe blooms from the steam by wrapping them in paper. Afterwardsarrange them in water in the usual manner.
Forget that Mimosa can be treated in the same way which will helpit retain its fluffy appearance. A little sugar in the water is also useful.