May is the busiest month for planting and transplanting and is the ‘transition’ month when direct sowing and thinning of crops begins to take over from transplanting.Root vegetables, apart from onions and leeks, should never be transplanted but this month the main crop of winter greens and brassicas – cabbage, broccoli, brussels sprouts etc., as well as summer cauliflower and broccoli, leeks, lettuce, asparsgus and calabrese, are to be transplanted. However, the transplanting of tender vegetables, including cucumber, courgettes, marrows, pumpkins, aubergines and peppers, is best left to the end of May, or even the beginning of June in our allotments as late frosts are the rule, rather than the exception, in Chipstead Valley.If you are not desperate for an early crop, dwarf and runner beans and sweetcorn can be sown directly into the ground from the end of May onwards and you can continue to sow other tender vegetables in the greenhouse for transplanting next month.The popular crops for direct sowing this month include beetroot, cabbage, cauliflower, peas, carrots, turnip, chicory, fennel, kale, lettuce and pak choi.