Soak seeds of non-woody plants before sowing: freshwater wetlands
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
Soaking seeds in water before sowing could increase germination speed and percentages, although the effect may vary between species (Marty & Kettenring 2017). This action involves soaking in water at near-ambient temperatures; other actions consider soaking in chilled or heated water.
To be summarized as evidence for this action, studies must have explicitly compared the performance of treated and untreated seeds. Studies that simply report the performance of treated seeds are not summarized here. Studies do not have to be in flooded/saturated soils, as long as they involve wetland-characteristic species.
Related actions: Soak vegetation before planting; Chill seeds before sowing; Heat seeds before sowing; Expose seeds to light before sowing; Physically damage seeds before sowing; Treat seeds with chemicals before sowing.
Marty J.E. & Kettenring K.M. (2017) Seed dormancy break and germination for restoration of three globally important wetland bulrushes. Ecological Restoration, 35, 138–147.
Supporting evidence from individual studies
A replicated, randomized, controlled study in 2015 in a greenhouse in Utah, USA (Marty & Kettenring 2017) found that soaking seeds of three bulrush species in water typically had no significant effect on their germination rate. Seeds that had been soaked before sowing had statistically similar germination rate in 24 of 30 comparisons (for which soaked: 6–88%; unsoaked: 1–75%). In the other six comparisons, soaked seeds had a higher germination rate (18–69%) than unsoaked seeds (4–50%). Five of these comparisons involved seeds whose dormancy had previously been broken through chilling and/or chemical treatments. Methods: Field-collected seeds of three bulrush species were sown onto sand in the greenhouse (36–72 sets of seeds/species; ≥100 seeds/set). Seeds in 18–36 random sets/species were soaked for two weeks before planting (in deionized water, changed every three days, 28–35°C). The other sets were kept dry. Some sets were also chilled and/or soaked in chemicals before soaking in water. After sowing, seeds were kept saturated. Germination rates for each set were recorded five weeks after sowing.Study and other actions tested