Q: We saw a distinct blue flower blooming all over Savannah. The stalk is about two feet tall and the blooms are a six-inch diameter ball. What is it?

A: You saw agapanthus, a great summer bulb for the lower South. It is native to southern Africa. Despite claims for “cold-hardy” types, it does not readily overwinter outdoors in Atlanta. The best idea is to put the bulb in a large pot and move it indoors when winter comes. Cut off the foliage and keep it inside until night temperatures are above 50 degrees in spring.