Dahlia hybrid Asteraceae Kristin Yanker-Hansen, Danville The single flowered orange and red dahlias that have recently been available through seed exchanges are mostly derived from Dahlia coccinea which comes from Mexico. This is a variable species from 2–4 feet tall that can have a long blooming period. They are wonderful to naturalize in coastal California but need to be lifted and replanted every four or five years to invigorate the clump. They take full sun, water, and survive heavy frost. Photo by Kristin Yanker-Hansen