Some commercial seeds are heat-treated or irradiated to extend shelf life, which can prevent germination.
Spice containers usually hold Brassica alba (yellow) or Brassica juncea (brown/Indian mustard). If you want specific ornamental or salad varieties (like 'Giant Red' or 'Mizuna'), it’s better to buy seeds from a garden center. Why You Should Plant Mustard 1. The Culinary Payoff can you plant mustard seeds