Allotment - the Where, When, Why and How - Growing Vegetables from Seed

Of course you're going to want to grow all your allotment vegetables from seed, and after a couple of years, you're going to start saving your own seed so that you can try to become completely self-sufficient in this area at least.

Germination basics - germination occurs best in temperatures between 18-25°C and later growing conditions should remain at 15°C at least. This means if you can set up these conditions in March, well and good, but if warm and bright conditions can't be guaranteed, hold off your sowing until April when conditions will be more favourable.

Differences in seed development - small-seeded crops such as tomatoes, peppers and aubergines produce tiny seedlings that grow slowly and this means that the earlier these can be sown, the better. One the other hand, larger-seeded crops, such as courgettes, cucumbers, melons, squashes and pumpkins and sweet corn will produce large, quick-growing seedlings. These can be sown later, in April or May - and it's worth delaying because otherwise plants may be ready before conditions are suitable on the allotment.

How to go about it - use a proprietary seed-raising compost, the famous John Innes number 2 is best, or make your own mixture of 50% perlite and 50% multi-purpose compost. Sow small seeds on the surface, barely covered with vermiculite or sieved compost and set the pots in a tray of lukewarm water until the surface darkens, then transfer the pots to a warm environment to germinate. A heated propagator is ideal, but a windowsill in a warm works too, or a heated greenhouse. Large seed should be buried its own size under the surface apart from pumpkins and squashes which should be set edge on in the soil and pressed down until you can't see them.

As soon as seedlings appear, move them to bright light but not overly hot sun. Water them to keep the roots moist, but avoid sogginess.

Seedlings allotment photograph by Daniel Morrison, used under a creative commons attribution licence