Ground Cover for Moist Ground?
Depending on what zone you live in, liriope (lilyturf) might be an option. There are two main varieties: clumping (L. muscari, I think) and spreading (L. spicata). L. spicata is more hardy (to zones 4-5), but the flowers are less noticeable. Lilyturf will take...
Annuals For a Blue Flower Garden?
I always have had good luck with bachelors buttons (cornflower). Very easy to grow from seed, prolific bloomers, good cut flowers. If you want just blues, rather than the more popular assortments, shop around for Blue Boy. Love-in-a-mist is also a good choice...
