1. Carrots: Carrots are dead cheap to buy, but even cheaper to grow. One packet of seed usually has several hundred seeds, and if you take a little time to sprinkle them, you'll get a 90-100% return on sowing. Carrots won't grow much in winter but you can sow a crop of baby carrots in a trough or planter bag. Keep it somewhere warm indoors until the seeds have germinated.

2. Celery: Plant a punnet. Six plants is more than most people need, but it means you can pluck the outer stems off each plant for a constant supply, rather than uprooting a whole plant. Twist and pull to harvest, and don't throw away the leaves. Chopped finely, you can eat them in salads, boil them up to make vege stock, or add to soups and stews. 

3. Cabbage. If you buy cabbages but only have the willpower to eat half of them, chop the uneaten portion in a food processor and freeze it in ziplock bags to throw into soups. You can still plant cabbages now but they won't heart up until spring.

4. Onions: you can start sowing these now. Sow the seed in a tray of potting mix or seed-raising mix that's about 10cm deep. Keep it in a warm place until the seeds germinate, then grow them on in the tray until the end of July, when you can transplant them outdoors. Onions take forever (at least six months) but it's satisfying to succeed with them.

5. Parsnips and swedes can be grated into soups; they're cheap and nutritious. 

6. Herbs such as rosemary, sage, thyme and Italian parsley are all hardy and handy for adding flavour to soups. Plant seedlings from the herb section at garden centres.