after the asiatic lilies are finished blooming it's best to cut them back by a third. top dress with compost and work some bone meal into the soil in the spring? not sure when. if you feed your lilies they'll come back every year. so yes they would be good cut flowers-just remember to cut the stamens off before you bring them in the house. they stain whatever they touch. zinnias are great cut flowers. a full sun annual that grows from seed quickly. amaranth, celocia, buddliea, dahlias, rhododendrons, wegelia, spirea. anything you can pick I suppose though some do better than others. hydrangeas usually hold up well for me. I always look for interesting leaves to add for structure in the arrangement. sometimes a few bare twigs works well. hope I have helped a little. ps give the roses another chance! a gardener such as yourself can do it!!
