With the start of autumn comes the thought of comfort food - warming casseroles and hearty soups. But why not give your kids their own veggie plot to encourage them to grow the ingredients to make their own soup?

Herts Advertiser: A vegetable plot growing the ingredients for carrot and coriander soup. Picture: RHS/PAA vegetable plot growing the ingredients for carrot and coriander soup. Picture: RHS/PA (Image: Archant)

It's an idea being encouraged by the RHS Campaign for School Gardening, which is running the Big Soup Share from October 7-13, when more than 1,000 schools will harvest and cook their own produce to share.

"You don't need acres of space. A couple of small pots can provide enough for several batches of soup," says Emma Griffith, RHS schools and groups content coordinator, who offers these tips on how to get started:

Plan your plot

Arrange your ingredients in a square so that everything you need to whip up a tasty treat is within easy reach.

Herts Advertiser: Emma Griffith and RHS colleague Elin Campbell Wooding harvesting vegetables at RHS Garden Wisley. Picture: RHS/PAEmma Griffith and RHS colleague Elin Campbell Wooding harvesting vegetables at RHS Garden Wisley. Picture: RHS/PA (Image: Archant)

Map out your 'soup square'

Mark out a growing area of 1m x 1m using string, and a bamboo cane or stick on each corner. If space allows, consider creating several squares to grow ingredients for different soup flavours.

Sow and plant

Following your plan, sow the seeds as per the instructions on the seed packet, or if you're short on time, buy plug plants (small, partially grown plants) which can be planted directly into the soil to give you a head start. Autumn is the ideal time to sow broad beans, garlic bulbs and overwintering onion sets.

Herts Advertiser: Recipes for minestrone soup often include beans, celery, potatoes and garlic. Picture: RHS/PARecipes for minestrone soup often include beans, celery, potatoes and garlic. Picture: RHS/PA (Image: Archant)

Look after your soup square

Check on your plot regularly and in the spring, thin out rows of seedlings where needed, to give them space to grow. Extend the growing season for crops planted earlier in the year by protecting from early frosts using fleece or cloches, and keep an eye out for pests. Water regularly, particularly in dry spells, and keep well weeded.

Add a garnish

Add a hit of flavour to soups or other recipes by growing herbs such as parsley, basil and chives. Even in the winter, many herbs can be grown on a sunny kitchen windowsill and simply snipped off the plant as needed.

Harvest

Reap the fruits of your labour when harvest time arrives, usually when the crop has ripened or the leaves start to die back. If you have a glut of produce, soup can easily be cooked and frozen, ready to warm up on the coldest of winter days.

Here's the RHS pick of classic soup combinations to try this year and next...

Carrot and coriander

Beyond orange, choose from a whole rainbow of carrot colours, including red, yellow and even purple. Some varieties can be sown in v-shaped drills as early as February - protect crops using insect-proof mesh to prevent carrot fly and get perfect carrots every time.

Aromatic coriander can be sown every few weeks from early summer to provide a regular supply, which can extend right into early winter if the seedlings are protected with a cloche. Watering often and growing in partial shade helps prevent plants bolting (flowering and then producing seed). When they do bolt, the seeds can be dried and used instead of fresh leaves.

Pea and mint

Peas are sown in early spring in flat-bottomed trenches that can be made using a hoe. For most varieties, you'll need to provide support for the plants to scramble up. Pea sticks made from twiggy branches are good for this and give a pretty cottage-garden look.

Ensure peas are kept well-watered so the pods swell - a good soak once flowering starts and another one two weeks later is ideal. Mint is best grown in a container for easy picking throughout the warmer months, and to prevent it spreading.

Minestrone

Recipes for this Italian soup often include beans, celery, potatoes and garlic. Beans such as cannellini are climbers that grow in a similar way to peas.

Consider growing dwarf borlotti beans in a small space, which don't need support, and can be planted in the summer to provide an autumn harvest of beans for drying.

Celery is one of the trickier crops to grow, but plenty of water throughout the growing season is the secret to a successful harvest.

Diced potatoes make a great soup thickener - grown from special 'seed' potatoes, they usually need to be left to sprout (a process called chitting) before being planted in the ground from spring onwards. Opt for blight-resistant varieties.

Pungent garlic is best planted in late autumn or early winter, but make sure the soil is well-drained and don't over-water, to avoid rot.

Get involved

Schools and community groups can sign-up now to take part in this year's Soup Share and receive a free event pack containing resources, such as soup recipes, posters and stickers at schoolgardening.rhs.org.uk/bigsoupshare