Sow From - April to June Crop From - November to January Seed Quantity - 600 Seeds Rely on Marian to produce a heavy crop of splendidly flavoured, finely textured globe roots which are resistant to both clubroot and mildew. A great but undervalued autumn and winter vegetable, swede is delicious mashed with carrot or diced in hearty stews and casseroles. Clubroot & mildew resistant. Winter harvest.