Do not use stronger solution than the manufacturer's recommendation. Avoid using water from a water softener. If a florist's porous foam material is used in assembling the arrangement, it is important that it is thoroughly saturated in advance in water containing a floral preservative. Use a vase large enough to keep the entire block of foam submerged. Be sure that the rose stems are inserted firmly, well below the solution level in the container.
Roses are thirsty flowers.
It is most important to check to see that the vase is full and add preservative solution often. Be sure foam materials are completely saturated and the container is full daily. Display fresh cut rose arrangement in a cool area out of direct sunlight and drafts. Premature wilting is not necessarily a sign that the rose is old. It usually indicates that air is trapped in the stem and the preservative solution cannot flow properly up the stem.