Cut the stems when the flower buds are just beginning to open. Cutting in the early morning is best. Submerge the cut ends in a bucket of lukewarm water and recut the stems at an angle, about 1 inch up. Display cut irises in a cool location isolated away from direct sunlight and drafts. Wilted flowers should be pinched off immediately. Check the water level every other day, refilling the vase when needed.