Think broccoli, cabbage and mustard varieties - all staple elements of your veggie garden.
Broccoli, cauliflower, cabbage, kale, brussels sprouts, mustard greens, kohlrabi, turnip, collard greens, mizuna, tatsoi, pak choy, bok choi, wong bok – the list goes on – these are all part of the brassica genus.
They are diverse in both their range and in the way that they are eaten – either as roots, leaves, flowers or stems.
Generally brassicas are cold-hardy vegetables and are grown over Autumn, Winter and Spring. But there are variations in the ideal planting times.
For example, brussels sprouts are best started in late Summer. They take four or more months to form sprouts - any less, and you can end up with a leafy plant with no sprouts.
By contrast, traditional Chinese vegetables such as bok choi and pak choy should not be started before late Autumn, as any hint of hot weather or water stress may see them bolt to seed before you have had a chance to enjoy them. The Japanese tatsoi is similar. Plantings can then continue throughout Winter (although growth will be slower). The main advantage of boy choi and pak choy, apart from being deliciously crunchy, is their quick time to harvest – a couple of months.
Plants such as broccoli, cauliflower and cabbage have a wide range of planting times (and, indeed, some sources say that broccoli can be planted any time of the year in temperate climates). However, I recommend planting in April or May. This means that your seedlings can establish themselves before the worst of the cold weather and the population of caterpillars from the white cabbage moth will be on the decline. Your harvest under these conditions will be early Spring.
Kale is an extraordinary vegetable that just powers on. Start planting from April and then continue planting right through Winter. The colder it gets, the crisper kale looks. It can take a few months to get the leaves to an appropriate picking size, but once that is achieved, you can continue picking every 2 weeks or so right through until November. If you are lucky, the plant may resist flowering and ‘going to seed’ in November and keep going right through Summer (although the leaves may get smaller and the caterpillars more numerous).
Kohlrabi is not commonly seen in backyard gardens, but is easy to grow and can be started in early Spring or Autumn. Avoid growing over the heat of Summer, as it can become woody. The time to maturity is fairly short, being 2 to 3 months depending on variety.
Mizuna is increasing in popularity and is one of the components often seen in salad mix, having a mild flavour. Start any time from late Autumn and then keep planting over Winter. Once the hotter weather arrives, mizuna will flower and seed, so make your last plantings late July or early August.
Mustard greens are leafy greens, sometimes with huge leaves (e.g. Red Giant) which have a hot taste if eaten raw, or no heat if cooked. Preferably plant over Winter, as they don’t like the hot weather.
Some interesting varieties:
Problem areas - Brassicas are susceptible in two main areas: a) heat (which makes them run to seed) and b) caterpillars from the cabbage butterfly. For both reasons, brassicas are not normally grown in extremely warm weather (the caterpillar population is killed by cooler weather).