Seasonal life-history trade-offs differ between plants derived from seed versus rhizomes in Saponaria officinalis

Many perennial plants reproduce both sexually through seeds and asexually through vegetative clones, and these contrasting origins can shape subsequent life-history strategies. Because clonal propagules begin with greater parental resource provisioning, whereas seedlings establish independently, these alternative origins create natural variation in early resource availability and developmental trajectories. This variation provides an opportunity to test predictions from life-history theory: while investment in current reproduction is expected to trade off with future growth or survival, such costs are often difficult to detect unless reproductive effort varies substantially among individuals or is experimentally manipulated. In this study, we compared growth, reproduction, and survival of seed- and rhizome-origin individuals of the invasive perennial Saponaria officinalis across three years in a common garden. We also manipulated reproductive effort in a subset of plants through pollen supplementation and tracked seasonal changes in flowering and seed production. Seedlings initially grew faster and made more branches and flowers than rhizome-origin plants, but by the second year rhizomes were larger and had more flowers. Seedlings also exhibited far worse survival than rhizomes. Across the flowering season, seed number per capsule declined, consistent with both increasing competition among flowers and declining resource availability. Pollen-supplemented seedlings had the most seeds per capsule early in the season and were the only group to suffer overwinter mortality, indicating a survival cost of elevated early reproductive investment. Overall, our findings show that reproductive origin influences allocation to growth, reproduction, and survival, with consequences for the establishment and spread of this invasive weed.