Sowing Vegetable Seeds

Rather than buying little plants from the garden centre, it is worth growing your own from seed. Most germinate easily, and the aftercare is not too arduous. In addition you will have a wider choice of varieties including many heritage vegetables.

A propagating case with a lid will help
with seeds that need a little warmth to

I have some vegetable seeds left over from last year. Is it still worth sowing them?

All seeds are dormant until favourable conditions arise that encourage them to germinate. Some are capable of surviving for many years – even centuries – in the dormant state. Vegetables are short-lived plants, however, so seed is best sown fresh. Most seed packets are stamped with a ‘sow by’ date. However, if you have any seed unsown in the packet from earlier years, it is always worth sowing it, but do not expect such a high proportion to germinate. The seed that does germinate should still produce excellent plants.

Do I need a propagator?

No. Seeds germinate at different temperatures, and these occur naturally in the garden. A propagator gives you more control, enabling 
you to achieve the appropriate temperature artificially. Seedlings raised in propagators need hardening off before planting outdoors.

What is sowing in situ?

Sowing in situ means sowing seed where you actually want them to 
grow – usually in a vegetable garden, though flowering annuals are also often sown where you want them 
to flower. This dispenses with the need to raise seedlings in containers and is often recommended for those crops that do not respond well 
to transplanting.

How do I prepare seed trays and pots?

Use a seed or multi-purpose potting mix. Fill pots or trays and water them well. Allow them to drain completely. The surface should be just moist to allow the seed to adhere to it.

How deep do I sow the seed?

Seed should be covered to its own depth. For instance, a large bean seed about 1cm (1⁄2in) across should be planted 1cm (1⁄2in) deep. Very fine seed can be surface sown. 
It is important that the soil is damp so 
that the seed sticks to it and is not blown away.

How do I sow very fine seed?

If seed can be sown individually, try
using modules – it makes transplanting
later much easier.

Seed that is too fine to handle individually can be sown in small pinches. Alternatively, take a pinch between finger and thumb and sow as thinly as possible in rows in seed trays.

What is ‘thinning’?

The seeds of some annuals and vegetables are too small to be sown individually, and outdoors should be sown in rows, as thinly as possible. When the seedlings emerge, it is important to remove a high proportion so that the remainder 
have adequate space to develop fully. If this seems wasteful, many vegetable seedlings can be added to salads – they are healthy and very tasty.

What is ‘pricking out’ and how do I do it?

If you have decided to germinate your seeds in pots or trays, once the seedlings have developed the second set of leaves they will need moving into larger containers to allow them to develop fully.

Prepare fresh pots or trays of potting mix. Handling the seedlings by the leaves, gently ease them from their original potting mix with a dibber. Use the dibber to make suitably sized holes in the fresh trays and drop in the seedlings. Gently firm them in, then water them well. Further potting on may be necessary as the seedlings grow. They can be planted out when large and sturdy enough and when conditions outdoors are suitable.

What is meant by hardening off?

Seedlings raised under cover need to be acclimatized to conditions outdoors before they are positioned there permanently. Remove the covers of the cold frame for part of the day – for an increasingly long period – over one or two weeks. The seedlings can then be placed outdoors in daylight hours, but in a sheltered position out of direct sunlight, again for increasingly long periods. Protect them overnight either indoors or in a cold frame.