Plants defend themselves from herbivory by either reducing damage (resistance) or minimizing its negative fitness effects with compensatory growth (tolerance). Factors mediating the selection for defenses such as herbivory and competition are in constant flux in an early secondary successional community, which can create temporal variation in selection for these traits. We manipulated successional age of the community and insect herbivory in a genotypic selection experiment with the perennial herb Solidago altissima. We found selection for investment in aboveground biomass in early succession but not in mid-succession, suggesting that the importance of competition is highest in the very first years of succession. Herbivory selected for smaller and better defended plants in both successional ages but decreased plant survival and probability of flowering only in mid-succession. Despite dramatic differences in herbivory between early and mid-succession, selection on defense traits did not change. These results demonstrate that changes in the community that affect key life-history traits in an individual species can occur over very short timescales in a dynamic secondary successional environment. Such temporal variation may be an important, yet overlooked, contributor to adaptive mosaics across populations.