The mustard plant was one of the first domesticated plants, according to Purdue University Extension. There are several varieties, including yellow, Oriental and brown, all of which grow in North America.
The germination period marks the beginning of the mustard plant's life cycle. Mustard is a cool season plant, and seeds can germinate at temperatures as low as 40 F. In the right conditions, it can emerge in as little as 5 to 10 days. Plant in fertile, well-drained loam soil for best results.
After the germination period, mustard plants should grow rapidly. Yellow mustard matures within 80 to 85 days, and Oriental and brown varieties mature within 90 to 95 days. Within 4 to 5 weeks of planting, the plants will cover the ground, and flower buds usually appear within 6 weeks. Blooming periods that last more than 15 days will create optimal crop yields.
Harvest mustard leaves when they are still young and tender. Yellow mustard seeds can be harvested by either swathing or straight combining. Oriental and brown varieties should be harvested by swathing, since they shatter more easily than yellow varieties. Harvest mustard in the morning when plant leaves seeds are yellow or brown. Cut the plants just below the lowest seed pods.