Despite their strange sounding name, brassicas are easily recognisable vegetables from the mustard family of plants, otherwise known as Brassicaceae. Vegies that belong to this family are broccoli, cauliflower, kale, cabbage, Brussels sprouts, radish, turnips, and even rocket.
A common attribute among brassicas are the seed pods they produce once they have flowered. Another is that they are cold and frost hardy, making them natural winter crops.
Brassicas were also dominant in European cuisine before the introduction of vegetables from the new world. I have highlighted three types of brassicas that are delicious in wintry meals—even more so when freshly picked from your own garden.
Cabbage is one of the most popular winter vegetables in Italy because it is readily available, inexpensive, versatile and easy to grow. No one really knows where cabbage originates, as it has been eaten for thousands of years. Romans, for example, ate cabbage for its health benefits. It is a leafy green or purple biennial plant, grown as an annual vegetable, whose foliage ranges from crinkly to smooth, and there are a number of cultivars available, such as savoy and purple. Plant them in full sun to maximise growth over the winter months.
Propagation: Cabbage prefers a rich, well-drained soil. It is best suited to temperatures of 4–24ÅãC: any hotter or colder forces the plant to flower early. Sow the seeds in late summer in propagation trays, with intentions to plant the seedlings into warmish soil in late autumn. This way the plant can become established before the weather gets cold. Space the seedlings 45 cm apart.
Watering: Water regularly for the first couple of weeks after you first put the seedlings in the patch, and then monitor the moisture levels. When the heads begin to form, a generous watering will greatly improve head size. Be sure to water evenly to reduce the risk of cracked heads or stunted growth. Once the plants mature you can cut back on the water to prevent splitting, but remember they’re still edible even if they split.
Mulching: Mulch to keep the ground cool and moist early in the season, with a mulch high in nitrogen. Remove or pull back the mulch in winter to keep the soil cooler and prevent it becoming too wet.
Feeding: Add a good handful of blood and bone and a tight fistful of potash per square metre to the soil before planting, or use a pelletised organic fertiliser as an alternative. Regularly water the plants with seaweed extract or fish emulsion every two weeks.
Pruning: No pruning is required.
Pollination: As this is a biennial plant, it won’t produce flowers and seeds until its second year/season. If you want to save seeds from your bumper crop, you will have to wait.
Pests and problems: Cabbage is prone to several nutrient deficiencies such as nitrogen deficiency, resulting in purpling of the leaves, as well as bacterial and fungal diseases such as powdery mildew. The biggest pest is the white cabbage moth and its caterpillars, and snails like the young seedlings. Whiteflies can also be a common problem.
Harvesting and storage: Cabbage variety and environmental factors will determine the harvest period. On average it will take around six months if you are growing them from seed before cabbages can be harvested. The head of the cabbage should feel nice and firm and be 10–45 cm in diameter, depending on variety. Use a sharp knife to cut the cabbage away from the stem. If you leave enough of the stem and the root system in the ground, you will get a flush of smaller, secondary growth. You can store your harvest in the fridge for up to two weeks, but it is best eaten fresh. Clean cabbages well before cooking, as they can harbour all sorts of insects.
Recommended variety: Cavolo Verza is a savoy cabbage that is also known as curlycabbage. It is a head cabbage with bright green, crinkly leavesthat is popular in northern Italy around Trentino.
Broccoli originates from southern Italy, so it is a vegetable close to my heart. The word ‘broccoli’ is itself Italian, meaning ‘flower crest of cabbage’. A robust vegetable, broccoli grows best in cool weather and likes plenty of sunshine. Start sowing seeds in late summer for a progressive harvest from winter to spring. You can attempt to grow a second crop over summer for an autumn harvest, but this will depend on your location, as hot weather often results in the plants bolting to seed.
Propagation: I buy broccoli as seedlings, as I don’t want too many plants; a couple is ample for a small vegie patch. If you’re keen for more, sow the seeds into propagating trays. The seeds are tiny, and you will have to do quite a bit of thinning out as they germinate. When planting out, space the seedlings 50–60 cm apart in a rich, moist, slightly acidic soil.
Watering: Broccoli grows best in moist soil, so regular watering is required, particularly in dry conditions. Water around the base of the plants rather than wetting the developing heads. Mulching: These plants have shallow roots, so mulch around the plants to suppress weeds instead of hoeing, which will damage the roots.
Feeding: Broccoli can be hungry and responds well to a fertiliser high in nitrogen. They will also benefit from regular doses of seaweed extract.
Pruning: Cut the florets regularly. This will encourage new heads to form on the stem and extend the harvest. Pollination: Let a couple of plants flower to attract beneficial insects and to form seed pods, which you can dry and store for the following season.
Pests and problems: The biggest problem for any member of the brassica family is the caterpillars of the cabbage moth: they will eat through a plant overnight. Sap-sucking pests such as aphids and whiteflies can also be common. Downy mildew can occur when the crops are wet and the weather starts to warm in spring, creating humid conditions. Broccoli can sometimes suffer from nitrogen deficiency, which will affect the bottom leaves of the plant first and continue upwards.
Harvesting and storage: Harvest broccoli when the buds of the head are firm and tight, before they open into flowers. Cut through the stalk just below the flower head. The plant will produce side shoots after the main head is removed, and you should be able to continue harvesting these other heads for some time to come. The harvest should last in the fridge for up to five days, but like all homegrown vegies, broccoli is best eaten the day it’s picked.
Recommended variety: Romanesco broccoli resembles a cauliflower, but is light green and has a pyramidal shape and many small flowers arranged in a spiral. I grow it because I think it looks cool, and it tastes great with pasta.
Kale has returned to the vegie patch in recent times thanks to healthy cookbooks and celebrity chefs spruiking its benefits. This is a good thing, as it is a great vegetable—it provides fresh, green foliage over a long growing season. Kale is thought to have originated in Scotland and has been cultivated for more than 2000 years. It was the most commonly eaten green vegetable in Europe until surpassed by the humble cabbage in the Middle Ages. Some varieties of kale are annuals, and some are biennials. It tastes sweeter and more flavourful after being exposed to a frost and, as a frost-resistant vegetable, it has traditionally been an important crop in cooler regions.
Propagation: Propagate kale in seedling trays in late summer so you can plant out the seedlings in autumn when they are about 5 cm tall. Space them about 40 cm apart in the patch. Kale grows best in rich, fertile soil in full sun. It loves the cold, and needs no frost protection. Good companion plants for kale include beetroot, celery, onion and potato.
Watering: Kale likes moist soil as much as it likes cool weather, so water well and regularly. This is the best way to ensure sweet, crisp leaves.
Mulching: Spread an organic mulch to keep down weeds. Mulching will also help keep the leaves free of soil, which might otherwise be splashed onto the plant during watering or rain, for a clean harvest. You could potentially remove the mulch in late autumn, when the chance of hot weather has passed, to cool the soil.
Feeding: Enrich the soil with compost and organic fertiliser before planting out the seedlings. While they are growing, apply a liquid feed or a side dressing (beside the plants) of pelletised organic fertiliser throughout the growing season to help keep your kale producing. Do this every 6–8 weeks.
Pruning: Always remove yellow leaves from the base of your plants to reduce the risk of fungal disease.
Pollination: Most kale varieties are biennial. Kale will cross-pollinate with other members of the brassica family, such as cabbage and broccoli. The seeds form in small pods. Allow them to grow fully on the plant before harvesting them to save seeds.
Pests and problems: Like other brassicas, kale is particularly susceptible to aphids, caterpillars of the white cabbage moth and slugs and snails. Soil-borne diseases can also be a problem, so practise crop rotation.
Harvesting and storage: You can begin to cut individual leaves off the kale when the plant is 20–25 cm high, starting with the outside lower leaves first.
Recommended variety: Tuscan kale, also known as cavolo nero (black kale).
Rocket is an edible, leafy green annual plant that has become popular in recent times. It is sometimes also called salad rocket, garden rocket and arugula, though this is very American. It has been cultivated for a long time in the Mediterranean and was thought to be an aphrodisiac. In areas of southern Italy it is used in a pasta dish called cavati.ddi; in Rome, it features in a meat dish called straccietti; and on the island of Ischia, off Naples, they make a liquor out of it. Overall, rocket is an easy-to-grow salad crop, which makes it a perfect vegie to include in your patch.
Propagation: Rocket can be planted throughout the year, though it tends to quickly bolt over summer, when the hot weather also makes the flavour very intense. If you want to plant it in summer, find a shady spot in the vegie patch. I prefer to sow rocket in autumn so I can harvest over winter and into spring, in which case it likes a sunny position. The seeds can be directly sown in the patch, or you can propagate them in seedling trays. If you direct-sow them, they will require thinning out to about 15 cm apart.
Watering: Keep the soil moist to prevent bolting.
Mulching: Mulch with an organic straw-based mulch once seedlings have become established to maintain soil moisture and suppress weeds.
Feeding: Rocket likes a well-fertilised soil; dig through compost prior to planting out seedlings. Apply liquid fertilizer once a month, as well as seaweed extract.
Pruning: No pruning is required, but cutting off unwanted flower heads will prolong the life of the plant.
Pollination: Rocket flowers require cross-pollination to form seeds. As with other brassicas, seeds form in pods.
Pests and problems: A common problem is that rocket will bolt rather than producing lots of leafy greens. This is usually caused by heat stress. Snails and slugs love to eat the young seedlings, and caterpillars also love the taste of rocket.
Harvesting and storage: You should be able to begin harvesting 4–6 weeks after sowing. Do so by treating plants as a ‘cut and come again’ crop, cutting out a section of the crop with scissors; or you can pick a few leaves here and there across the whole crop. Picking regularly encourages rocket to stay bushy and keep producing. Pinch out flower buds as soon as they appear, otherwise the plants may bolt to seed. These young white flowers can be eaten as well. It’s best to pick leaves when they’re young, as the flavour and spice intensifies as they age.
Recommended variety: Rucola Selvatica is a wild rocket with small, fine leaves that have an intense flavour. Wild rocket is a perennial that is commonly available in many nurseries these days.
Adapted from Growing Food the Italian Way by Fabian Capomolla (Pan Macmillan 2017)