Though they can be sown direct, a foolproof way to grow healthy swedes is to sow them in module seed trays – sow one or two seeds in each module of the tray 2cm deep. Thin out the weaker seedling. They will germinate in about a week and will be ready for planting about a month later. Harden off early sowings. Plant seedlings out, spacing 30cm between rows and plants. Do not plant turnips where there have been brassicas for at least 3-4 years previously. Since swedes store well it’s worth putting some thought in to growing for winter storage – if you sow 30 swedes in May or June, they will be ready to lift in October and will last you from October to April (consuming one a week).