Typically, you can expect your fresh flower arrangement to last at least seven to 12 days. If your bouquet arrives in bud form, they can last even longer. Following the stem-trimming instructions and adding flower food can also help maximize the longevity of your blooms. Generally though, you should change the water every day and make sure that there isn't any foliage in the water. If you're out of flower food, dropping a clean penny into your vase may help keep flowers alive longer.