Mums arrived in North America from Europe in the 18th century but long remained a minor player in the garden market. Then, in the 1930s and '40s, researchers discovered that by artificially lengthening the plants' night hours, they could bring mums into bloom at any time. Growers quickly realized the market potential of mums — lots of beautiful plants on a quick cycle. Breeders got busy, and the result is today's mind-boggling array of mum choices.
