You may still be reaping the rewards of all your hard work on the allotment or vegetable patch this year, but don’t down tools just yet as there are winter crops which can be planted in autumn to fill the gaps.

Not only will new crops keep the soil covered over winter and help to suppress weeds, you’ll have a bonus crop of quick-maturing vegetables before the winter closes in – while some are hardy enough to keep harvesting through until early spring.

Others will get a head-start on spring-sown crops and should be ready several weeks early.

Which? Gardening, the Consumers’ Association magazine, trialled a number of veg including onions, peas, beans and winter salads to see how they would fare planted in the autumn.

The trial, featured in the September edition of the magazine, found that garlic is a crop worth starting in autumn unless you’ve got cold, wet soil – in which case, wait until February.

Buy or order the bulbs now, but wait until November before planting them. Split the bulbs into individual cloves just before planting, about 15cm apart. Ease them into the soil, and make sure their tops are hidden or the birds may take them.

They should produce plants about 15cm tall before winter, which will be tough enough to survive the season, and you should be harvesting them by July. The garlic variety ‘Solent Wight’ was best in the magazine’s last trial.

You can also plant onions in the autumn, spacing the sets 10cm apart in rows 30cm apart during October or November. These will overwinter like the garlic and should be dried off and ready to harvest in mid-July, a couple of weeks before spring-planted onions. Try the varieties ‘Electric’ and ‘Radar’.

Peas and broad beans can also be sown in October and November, provided you choose a sunny, sheltered spot. Sow broad beans in double rows with 20cm between plants each way, to make it easy to support the plants in spring, by running string round the outside tied to posts at the corners.

With peas, dig out out a shallow trench 3-4cm deep and at least 15cm wide. Scatter seeds roughly 5cm apart each way. The plants should reach 15-20cm tall before they stop growing in mid-winter.

The traditional broad bean ‘Aquadulce Claudia’ is a safe bet, but the small-podded ‘Stereo’ is also worth trying.

You may have success if you make September sowings of carrots, beetroot, radish, turnip and kohl rabi, spinach and leaf beet. Reliable types include the carrot ‘Early Nantes’, lettuce ‘Little Gem’ or ‘Salad Bowl’ and beetroot ‘Boltardy’. Success will depend on the weather.

Give the area a good soaking several days before you sow, especially if the weather’s been hot and dry.

Aim to harvest before the first severe frosts, or cover the crops with fleece to extend the season.

The full report is in the September issue of Which? Gardening, a subscription-only gardening magazine published ten times a year. For details on how to receive three issues of Which? Gardening for £3, telephone (01992) 822800, or visit which.co.uk.