Cover potatoes if frost threatens. Prepare sites for growing marrows & pumpkins outdoors, sowing & thinning the seeds later in the month. Prepare planting sites for outdoor tomatoes. Sow French beans outdoors. Set out late summer cauliflowers. In the north, plant out Brussels sprouts. Make further sowings of summer spinach & salad crops. Sow long-rooted beetroot for storing for winter use. Sow runner beans & erect canes or poles to support them.
Under glass
Gradually remove cloches from spring cabbages, carrots, lettuce & broad beans. Prepare sites for growing cucumbers in frames or cloches. In the north, sow runner beans under glass for planting out in June.
Less common vegetables
Continue cutting asparagus. Order self-blanching celery plants for June planting. Sow seakale beet, scorzonera, salsify & sweet corn.