The National Gardening Association gives a tip on how to tell the difference between annuals and perennials in a wildflower mix.
Q. I planted a wildflower seed mix. Can you tell me which are annuals and which are perennials, and how long after planting each should take to bloom? The area is starting to look "weedy" and I'm afraid my neighbors are going to complain before the flowers bloom. Flowers in the mix: white yarrow, cornflower, partridge pea, lance-leaved coreopsis, larkspur, California poppy, Gaillardia, baby blue eyes, corn poppy, black-eyed Susan, blue salvia, crimson clover.
--L.C., Alpharetta, GA
A. Some of the most appealing aspects of wildflower mixes--they're carefree, have many different plant heights, leaf shapes and blossom colors--are also some of the objections people have to them. Some consider them to be unruly and weedy-looking. Wildflower mixes have their place, though, and when your wildflowers begin to bloom, your neighbors will appreciate your gardening prowess. All of the plants listed are perennials in your gardening zone. Most should begin to bloom in early summer, depending upon your weather, and should be in full bloom by midsummer. Enjoy your wildflower garden, and cut a small bouquet or two to share with your neighbors.
--National Gardening Association