Now the soil is warming up, sow your Runner Beans and French Beans and make further sowings of Carrots, Beetroot, Summer Cabbage and Cauliflower, Leeks, Radish and Salad Crops. If you made an earlier sowing of Salad Leaves, Spring Onions or Radishes you may have some large enough to use already, don’t leave them until they are full size – the secret is to start harvesting as soon as you can - that way they won’t run to seed before you have time to eat them all. Covering them with Insect Netting or a Micromesh Tunnel will keep out carrot and cabbage root-fly whist also giving some protection from cold nights.
Continue harvesting the last of your Sprouting Broccoli, Leeks and Kale, sprinkling some Organic Extra around the plants will give them a final boost before they finish cropping. You can sow Peas in succession from now until June to give you a really long cropping period. Sowing a short row every 2 weeks will give good continuity of cropping. Applying a top dressing of Organic Extra a day or two before any planting will release nutrients to your plants over a long period and add humus to your soil.
Sow Sweetcorn in pots in the greenhouse in May, they will produce strong plants ready to plant out in June. Courgettes, Marrows and outdoor Cucumbers can be sown in situ from the middle of the month provided the weather is warm enough, if it is still a bit cold start them off in the greenhouse or on your kitchen windowsill, or plant them out and give some protection with Fleece or a Cloche. Make sure you keep all emerging seedlings and young plants well watered. Sweetcorn is wind pollinated and best planted in large blocks, so the male flowers at the top of the plant can pollinate the female tassels lower down.
If you are gardening in the north of the country bear in mind you may need to sow everything a bit later, be led by the weather and the condition of your soil, not what it necessarily says on the packet. Please don't be tempted to transplant outside too early, there is nothing more disheartening than growing lovely little plants only to have them wiped out by a late frost – it could put you off growing forever - so be warned! If in doubt wait a week or two.