Previous work shows that individuals of the keystone cactus Carnegiea gigantea found in slower-growth, more arid populations live longer than those in wetter areas. This study follows by adding data for youth for these populations. The median age and the cut-off ages for the youngest deciles confirm that populations in wetter areas with faster growth have the most compressed life cycles, exhibited at all life stages. Populations are more youthful in wetter, faster-growth environments.