Keeping Daisies Fresh in a Vase
Daisies are very thirsty flowers. Keep the water level in your vase high, adding water at least every other day. Every day, cut about 3/4 inch off the end of the daisy stems to allow them to absorb water better. Change the water regularly, and remove any leaves or petals which might be floating in it, as they may spread bacteria which could shorten the life of your flowers. Well-cared-for daisies can last five to seven days.
Keeping Carnations Fresh in a Vase
Carnations are sensitive to ethylene, a chemical produced naturally by fruit and vegetables as they ripen. Keep your carnations away from any fruit and vegetables to prolong their life. Cut the stems every day, as you do for your daisies, but make sure to cut them above one of the nodes on the carnation stem, so as to allow the stem to absorb water more easily, and cut them under running water. Carnations can last from one to four weeks if you care for them properly.
Change water and cut your flowers' stems at least every other day to keep either daisies or carnations lasting as long as possible. If you have to choose between them, remember that carnations will naturally stay fresh up to four times as long as daisies.