Most seeds sink in water. Seeds typically germinate mid-spring through early summer. Upon germination, seedlings float to the surface. Seeds under cold dry storage remain highly viable for at least 3 years, but longevity under field conditions is unknown. Seedlings can mature and flower within 8-10 weeks.
Seeds lack a dormancy period.
Seeds stored in dry soil at room temperature can survive for at least 14 years, but longevity under field conditions is unknown. Most seeds germinate in spring when conditions become favorable. Fall-germinated seedlings may overwinter under mild conditions. Seedlings typically emerge after water levels subside. Monitoring uninfested areas and hand-pulling newly discovered seedlings before seed is produced can help prevent the spread of purple loosestrife .