QuestionsHow to growVegetable GrowingWinter swedesSwedes 0 Vote Up Vote Down Padraig Griffin asked 13 years ago I seem to have a problem with getting my swedes to swell to any reasonable size, they have plenty water and rich soil. 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 5 years ago Perhaps you sowed seeds too late. Sow between mid-may and mid-July. They need to be thinned out to about 20 to 30cm apart. If the soil is very rich in nitrogen, they may grow a lot of leaves and not much root.