The soil seed bank and seed germination capacity of Poa annua in the vicinity of the Polish Antarctic Station (South Shetlands, Antarctica) were investigated. It was documented that annual bluegrass can reproduce sexually and produce a functional seed bank of close to 5000 seeds/m2 under maritime Antarctic conditions. Comparison of germination between Poa annua and two native plant species revealed that Poa annua seeds can germinate as fast or even faster than native species, and are more vigorous. Our studies show that in the Antarctic Poa annua can successfully reproduce sexually and produce fully developed, viable caryopses that are able to survive the maritime Antarctic winter, not only in a soil bank, but also directly in the previous year's inflorescences.