May to June. The mature harvest season of rapeseed is generally from April to May every year. After harvest, it takes about one month to dry rapeseed and collect fresh rapeseed to make new rapeseed oil, so the new rapeseed oil will be on the market from May to June. The new rapeseed oil has good taste, higher nutritional value and higher market price. When purchasing, you should carefully ask the personnel at the point of sale for comparison and check the production date of rapeseed oil.