This article has been checked for horticultural accuracy by Oliver Parsons.

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What are brassicas?

The brassica family includes nutritious vegetables such as broccoli, cauliflower, kale and Brussels sprouts. These plants are genetically similar and share many characteristics, such as being hardy and requiring fertile, free-draining soil.

Brassicas are renowned for their distinctive flavours, which range from mild to spicy, depending on the type and part of the plant that's eaten. They also have many health benefits, being rich in vitamin C, vitamin K, beta-carotene and glucosinolates, which are compounds that may help prevent cancer. Brassicas are also a great source of soluble fibre, which can lower cholesterol and improve digestion.

Brassicas can be grown all year round, depending on the variety and season. Some of the easiest to grow include radishes, kale and mustard greens. These are hardy, adaptable to various growing conditions, and have relatively short growing periods, making them ideal for beginners. Cauliflower and Brussels sprouts can be more challenging to grow as they require specific conditions, such as consistently cool temperatures, and require plenty of space. They also have longer growing periods and may require more extensive protection against pests and diseases.

Many brassicas can be grown from seeds or plug plants. Radishes are the quickest to mature, often being ready to harvest four weeks after sowing. Rocket and mustard greens are also fast growing and can often be harvested within six weeks. Brussels sprouts and cauliflower have longer growing periods, with cauliflower maturing in three to six months, while Brussels sprouts can take seven months to produce a crop, depending on the variety and growing conditions. Growing brassicas isn't difficult if you follow simple tips for feeding and protecting your brassicas from pests. Patience is key when growing some brassicas, but the results are usually worth the wait.


What do you feed brassicas?

Brassicas are heavy feeders, meaning they require a lot of nutrients to grow properly. This is especially true of those that are in the ground for a long time, including Brussels sprouts and cauliflowers. Before planting, enrich your soil with compost or well-rotted manure. Then, around four weeks after planting, start applying an organic liquid fertiliser every week or so. It's also a good idea to mulch around your brassicas with compost to retain moisture and suppress weeds.

Crop rotation is another important practice when growing brassicas. Avoid planting them in the same spot for more than one season in a row. Instead, rotate them with other crops, such as legumes or root vegetables, to prevent diseases such as clubroot taking hold.


How to protect brassicas from pests

Protection netting on brassica bed
Protection netting on brassica bed

One of the biggest challenges when growing brassicas is dealing with pests. Common pests that affect brassicas include pigeons, caterpillars, aphids and flea beetle. While pesticides can be effective, they can also harm beneficial insects and pollinators. Instead, try these organic methods to protect your brassicas instead:

  • Cover your crops – use a very fine mesh netting to protect plants from pests such as flea beetle, egg-laying moths and butterflies (which produce caterpillars) and birds. These net cloches allow sunlight and water to pass through while preventing pests from getting in.
  • Handpick pests – if you see pests on your plants, pick them off and dispose of them. This method works well for larger pests such as caterpillars.
  • Grow companion plants – some plants, including French marigolds, are thought to help deter certain pests such as aphids from brassicas, while nasturtiums can be used as a sacrificial crop that will be even more attractive than your brassicas, thus luring the pests away

Broccoli

Broccoli 'Green Magic'
Broccoli 'Green Magic'

The broccoli you find in the supermarket is known as calabrese. It's high in fibre and vitamin C. It can be enjoyed raw or cooked by boiling, steaming, roasting or stir-frying. It's a cool-season crop that grows best between 15-18°C and you should get a harvest 14-18 weeks after sowing. As well as the calabrese types of broccoli, which are typically harvested from midsummer to mid-autumn, you could also try growing purple sprouting broccoli, which is planted from summer to autumn and overwinters in the ground for a very early spring crop.


Cauliflower

Cauliflower
Cauliflower

This cool-season crop is high in vitamin C and can be grown in a range of colours, including white, orange and purple. Cauliflower can be eaten raw or cooked by boiling, steaming, roasting or mashing. It can also be used as a low-carb substitute for rice or potatoes. Cauliflower grows best between 15-18°C and can be harvested three to six months after sowing.


Kale

Kale
Kale

This leafy green is easy to grow and rich in vitamins A and C. Kale can be eaten raw or cooked by boiling, steaming, sautéing or baking into crisps. It can also be added to smoothies or salads. It's one of the hardiest brassicas and can be grown in a range of temperatures. Pick kale as you need it, from late summer through to late winter.


Brussels sprouts

Brussels sprouts
Brussels sprouts

This festive veg has a distinctive flavour and can be eaten raw or cooked by boiling, steaming, roasting or frying. Brussels sprouts are rich in vitamin C, fibre and glucosinolates. They are slow-growing plants, taking around 30 weeks to produce a crop, with sprouts ready from autumn through to late winter. They grow best between 15-18°C.


Cabbage

Head of savoy cabbage
Head of savoy cabbage

Cabbages can be eaten raw or cooked in various ways, such as boiled, steamed, sautéed or fermented into sauerkraut or kimchi. Rich in vitamin C, there are many types of cabbage to choose from, including leafy spring types to hearting winter varieties. Cabbages can be grown in a range of colours, including green, purple and white. This veg does best between temperatures of 15-18°C and can be harvested in spring or autumn.


Kohlrabi

Purple kohlrabi, ready to harvest
Purple kohlrabi, ready to harvest

Kohlrabi is faster growing than many brassicas, with mature 'bulbs' (actually swollen stems) ready in around 12 weeks, although you can harvest baby veg from eight weeks. It's known for its unusual flavour, often likened to that of a broccoli stem, and can be eaten raw or cooked by boiling, steaming or roasting. It's high in fibre and vitamin C, and grows best in cool weather at 15-18°C. Harvest in spring or autumn.


Turnips

Freshly harvested turnips
Freshly harvested turnips

Turnips are one of the easiest brassicas to grow and are useful plants for those keen to maximise the season, as maincrop varieties can be harvested through most of winter. With many types available, it's possible to harvest turnips almost year round. They are high in fibre and vitamin C and can be eaten raw, or cooked by boiling, roasting, mashing or pickling. The leaves of turnip are also edible and can be cooked like spinach. It's a cool-season crop, growing best at 10-18°C.


Swede

Swede, also known as rutabagas
Recently harvested swedes

Swede is sweeter than turnip and can be eaten raw, or cooked by boiling, roasting, mashing or baking into chips. It's high in fibre and vitamin C. Swede grows best in cooler summers and can be harvested in autumn and winter.


Radishes

Row of radishes
Row of radishes

High in fibre and vitamin C, radish is loved for its crunchy texture and peppery taste, and is usually eaten raw, although some varieties can be prepared by boiling, roasting or pickling. It's a fast-growing crop and is happy in a range of temperatures. Sow from late winter to late summer, and harvest 4-5 weeks after sowing.


Mustard greens

Mustard greens in a cold frame
Mustard greens in a cold frame

Try these spicy leaves picked young and served raw in salads, or let them grow to maturity and cook them like spinach and chard. They can be prepared by boiling, steaming, sautéing or stir-frying. Mustard greens are easy to grow and are rich in vitamins A and C. It's a fairly hardy crop which can be grown in a range of temperatures and harvested throughout the growing season.


Pak choi

Pak choi 'Rubi F1'
Pak choi 'Rubi F1'

Pak choi, also known as bok choy, is an oriental brassica. This leafy green is high in vitamins A and C. It's a cool-season crop, happiest at 10-21°C; when growing at higher temperatures it has a tendency to bolt. It can be harvested in spring or autumn.


Rocket

Rocket leaves
Rocket leaves

Rocket is a fast-growing crop with a peppery flavour, and is high in vitamins A and C. It's happy growing at a range of temperatures and can be harvested throughout the growing season, for use in everything from soups and pasta sauces, to salads and pizza toppings.


Broccoli raab

Bunch of Cima di rapa (Brassica rapa). Getty Images
Bunch of Cima di rapa (Brassica rapa). Getty Images

Broccoli raab, often sold as 'Cima di rapa', is a leafy green with a bitter and nutty flavour. High in vitamins A and C, it can be boiled, steamed, sautéd or stir-fried. It's a cool-season crop, growing best at 10-21°C, and it can be harvested in spring or autumn.


Chinese cabbage

Chinese cabbage
Chinese cabbage
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This leafy green is high in vitamins A and C. It has a mild and sweet flavour, and can be eaten raw in salads or cooked by boiling, steaming, roasting or stir-frying. It's a cool-season crop that grows best at 10-21°C. Chinese cabbage can be harvested from late summer to late autumn.

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