Seed Storage Conditions Shape Germination Outcomes: Differing Responses in Two Closely Related Grass Species

Seed dormancy is a protective adaptation meant to reduce the risk of germination in unsuitable or unpredictable conditions. However, dormancy can complicate or undermine restoration efforts if care is not taken to understand how dormancy-influencing seed storage conditions can affect germination outcomes. Additionally, assuming that closely related species will respond similarly to the same storage and germination conditions may obscure important life history differences, potentially leading to ineffective or biased restoration strategies. We examined how seed storage conditions influence germination outcomes in two foundational grassland species (Festuca hallii [Vasey] Piper and Festuca campestris Rydb.) by subjecting seeds of both species to different combinations of storage duration, temperature, and moisture, before conducting a germination assay under identical controlled conditions. We found that the two species had drastically different responses. F. campestris exhibited low overall germination (13%), which was not meaningfully influenced by any of our storage treatment combinations. F. hallii, meanwhile, had a mean germination of 69%, which increased to 94% simply by soaking the otherwise untreated seeds for 24 h before the germination assay. Our findings highlight the importance of considering seed handling and storage as critical steps in the restoration pipeline, with the potential to significantly impact germination and establishment success. They also highlight the need to consider species-specific management strategies, even among closely related taxa, and for clear communication among seed suppliers, land managers, and restoration practitioners to ensure shared understanding of seed histories and conditions before planting.