Abstract: The invention provides a seed treatment method comprising: (i) mixing starting materials (7) comprising an aqueous liquid (2), anaerobic bacteria (1), a substrate (3) for the anaerobic bacteria, and seeds (4), to provide a mixture (10) having a void volume (15) between the seeds, wherein at least 50% of the void volume comprises the aqueous liquid, (ii) storing the mixture in a condition to prevent oxygen from entering the mixture during a treatment time, to provide treated seeds (9), wherein the treatment time is at least 6 hours and at maximum 14 days, and (iii) collecting the treated seeds (9) from the mixture (10).