Understanding the mechanisms that are responsible for maintaining genetic variation continues to be the focus of much research in evolutionary ecology. It has been suggested that the abundant genetic variation found in Lobelia inflata is maintained by fluctuating selection coupled with temporal genotype-environment interaction. I begin by asking whether microsatellite genotypes exhibit variation in key life-history traits including timing of germination, bolting, flowering and maturation. I used a common garden experiment to show that phenotypic variation exists, that this variation occurs in life-history traits, and that this variation has a genetic basis. Next, I looked at how the microsatellite genotypes that differed in life-history traits expressed differential fitness across environments in a “space-for-time” experiment: I grew multiple lineages under varying conditions to simulate differing natural conditions. Results offer tentative support for the hypothesis that fluctuating selection is responsible for maintaining variation in this system.