Winter rapeseed is mainly grown in Poland, with its crops occupying 95% of the area of all oilseed crops.

An excerpt from the article 24 facts about rapeseed

Seeds are sown in August, germinating as early as a week after sowing into the ground. Even before winter, rapeseed produces a short stem covered with several leaves. Full development and flowering occurs in the spring. The first flowers appear in May, although in warmer areas of the field, they can bloom as early as April.