Sow February-April. Harvest June-September. Scatter your seeds over well-raked soil in a bright, sunny area. In colder districts you can sow the seeds in small pots indoors and plant them out at the end of May. Space plants at least 20cm (8") apart, water well and watch them grow. Within 30 days of germination, mustard will develop a mature canopy. Within 35-40 days of germination, it will begin to bud. The flowering period lasts around 7-15 days. Pods develop from the flowers over the course of the next 35-45 days. The seeds in these pods are mature when the pods begin to turn from green to tan or brown.