Article: Jackie French (Canberra Organic – Spring 1995)

Cabbage
Image: MonicaP on Pixabay

I fell in love with cabbages the day I realised they didn’t have to be boiled. That was in the sixties, when coleslaw was an avante garde American import – and even though Mr Doo, our chinese neighbour, had been eating his cabbage stir fried within sniffing range ever since we moved in, it wasn’t till the early seventies that I discovered that cooked cabbage could be good too.

Cabbages are now one of our winter staples. We rarely eat cabbages in summer, keeping them for a winter treat. Cabbages aren’t much good in summer – flabby, with a stronger ‘cabbagey’ flavour – the very faintest tinge of heat induced rot.

Cabbages need winter frosts to be crisp and sweet, and then they can be superb. I plant great big cabbages to boast about (you can give a slab away to friends), red cabbages for colour, and tiny sugar cabbages for a single meal. A giant cabbage is a thing to boast about – unless you’re into cow pumpkins it’s the most massive thing you’ll ever grow – and after all anyone can grow a massive pumpkin.

We eat cabbages raw, grated with raw beetroot and raw carrot and a few sunflower seeds, and masses of mustardy vinaigrette dressing (sounds horrible unless you’ve eaten it: its excellent, and even kids love it), or stir fried with a little soy sauce, or fried with tomatoes and onions, or steamed then each leaf stuffed with mince or old fried rice and simmered in stock, or fried with leftover potatoes and maybe just a little bacon, which is one of those magic dishes that tastes infinitely better than any of its ingredients. There’s also a luxurious version of this — layers of chopped cabbage and sliced potatoes with just a little chopped onion in an oven dish, with cream poured on top and very slowly baked till the top is brown and bubbling. Wonderful.

You can plant cabbages till the ground feels cold when you sit on it. After that they’ll go to seed in spring before getting fat enough to make a good feed (Though you can eat cabbages that are just going to seed – even the stalk is good if sliced thinly before the flower heads form and it gets tough). Some varieties also resist going to seed in spring. When in doubt buy the punnets of cabbages available at the garden centre – usually they’ll be the right variety for your area and that time of year.

While you’re down there of course you can stock up on other brassicas – broccoli, caulies, even brussels sprouts if you’re that way inclined. It’s now probably the wrong time of year in most areas to put seeds in – but if you’re in a frost free area seeds are a far cheaper way to grow your greens.

The three rules for good cabbages (or broccoli, cauliflower etc) are:

  • plant them to mature in cool weather – either late summer, autumn, winter or early spring
  • feed them well – brassicas like cabbages and caulies and broccoli ‘sulk’ if they’re not fed properly. I’ve had starved cabbages in a patch of the garden do nothing for two years – then suddenly decide to heart when I hadn’t even bothered to look at them for months. (You can in fact make use of this sulking habit – plant four seedlings together – the ‘dominant’ seedling will mature – but the others will wait till they have room and inclination – this is an easy way to stagger your crop with one planting. Never plant a clump – or even worse – a row of cabbages. Don’t plant them on the outskirts of the garden either.

Pests, especially cabbage butterflies and moths, find their food supply in two ways – either by scent or appearance (often by silhouette). Brassicas have a very distinctive shape. The more you interplant your cabbages. the less of a pest problem there’ll be.

This year, for example, I’ve got one lot of broccoli planted on the terrace by the kitchen. It’s an almost complete failure – the shapes are very visible to any pest that flutters by – and another lot disguised among parsnips and dahlias. They’re doing fine – even though they are only a few metres away.

If you are really worried by caterpillars, MAKE SURE YOU LET A FEW BRASSICAS GO TO FLOWER. Most pests are lazy – they’ll lay their eggs where they feed. If you let a few broccoli plants flower, they’ll last for years if you keep snipping them. You’ll find most of the eggs are laid on them, after the butterflies have fed on the nectar from the flowers.

Our best defence here are the annual wild turnip weeds. They flower through most of summer – and their presence is enough to protect the cabbages crop nearby.

Other brassica problems

Spindly broccoli

This has been starved. Feed the poor thing and it’ll feed you (old hen manure etc is excellent – broccoli need more nitrogen than other brassicas, as they give more crop per plant if you keep harvesting the heads).

Don’t just pick the central broccoli head. The more you pick your broccoli the more you’ll get. The heads will be progressively smaller, but there’ll be more and more of them. I once kept a broccoli plant going for three years. Then I went on holiday and the whole lot went to seed and toughened. By then it was enormous. At the moment we’ve got rather dwarf-looking cabbages that we’ve been harvesting for two and a half years. They produce small, brussel-sprout like heads at irregular intervals.

Puffs’ Brussel Sprouts

If your brussel sprouts aren’t firm it’s either too hot; or you used too much nitrogen to feed them (mulch instead for both problems). In a trial plot here, compost-fed sprouts planted at the same time as urea-fed sprouts yielded an excellent crop – the urea fed crop gave a few puffy blobs then went to seed.

Puffy or Gone-to-Seed-Cabbage

Cabbage can be sown at any warm time of the year, though the firmest heads come from cabbage planted after Christmas for autumn winter and spring. Cabbage can go to seed quickly in hot weather. Pick cabbages as soon as the head seems to elongate – at this stage its getting ready to burst to seed. Puffy cabbage have had too much nitrogen and too much heat and water. Give a more balanced feed, especially if you like summer cabbage.

Like brussel sprouts, compost fed cabbage tolerates extremes more than cabbage fed on a high nitrogen fertiliser. If you must use a high nitrogen fertiliser like dynamic lifter or hen manure, try to give a fortnightly dose of liquid foliar seaweed spray to help check nutritional imbalances.

Purple or Tough Cauliflower

Summer caulies turn purple and become tough. Wrap the outer leaves around them to keep them soft, white and tender (sounds like a detergent commercial for your hands). New varieties don’t have enough leaves to wrap round the heart – avoid them. Beware of ‘miracle maturers’, too – caulies that are supposed to heart early. Most I’ve tried here have matured at the same rate as the non hybrids – but only with enormous quantities of fertiliser and water. They don’t hold as well as old fashioned ‘paleface’ either.

Try cutting off the head of the cauliflower – don’t pull the whole thing up. Small heads should then form around the stalk. These can be eaten too. Once the stalk starts to rot, though, remove it – it will inhibit other plants.

Aphids

Plant the caulies/cabbages etc later – you have probably planted them too early; add potash to the soil with wood ash, comfrey or compost; hose them strongly; make a spray of glue and water to suffocate them.

Know Your Enemy

Humans have a contradictory attitude to pests – on one hand we are so frightened by them we use stronger and stronger poisons to (unsuccessfully) eradicate them; on the other hand we have too much contempt for them to understand them.

The more you understand your pest, the easier it will be to grow a crop that will be able to tolerate their presence.

Eradicating pests doesn’t work – there are always more where they came from – so you have to keep spraying and the pests become resistant while the predators are zapped, or simply move away to a place with a more regular food supply.

The worst pest problems come where there are pest booms and busts – a ‘no pest’ stage after spraying; then pests build up quickly without predators to control them.

The following is a short run down on cabbage caterpillars (the larvae of cabbage white butterflies and cabbage or diamond-back moth), and their parents – a few methods of controlling them, and, as a last resort, killing them. Unlike conventional growing, organic growing has infinite ways of controlling pests. Once you understand your pest problem, you wiIl probably be able to work out many other ways of attacking it.

About a decade ago I grew 2,000 caulies. By the time they were finger size they were supporting a healthy population of caterpillars. I began to go through them, squashing them (this isn’t as labour intensive as it sounds and is still the best caterpillar killing method I know). After ten days I noticed that there were far fewer caterpillars – though still plenty of butterflies. There were also many more wasps (three sorts), yellow robins, and probably many other predators. At the end of three weeks I stopped squashing them. The crop grew fat and healthy, and was sold through regular commercial channels.

IT IS POSSIBLE TO ENTIRELY CONTROL MOST PEST PROBLEMS WITH NATURAL PREDATORS.

In the case of caterpillars, you need:

  1. a regular supply of pests to keep your predators eating all year long – otherwise they’ll die or move away;
  2. flowering plants to attract predators – especially flowering brassicas see above; nearby water also helps;
  3. minimal to nil pesticide use.

Actually, predator attracting is a subject in itself – I could go on for pages. But the three elements above are perhaps the most important. I also find no-dig beds here have fewer pests, possibly because one of our best predators is a ground dwelling wasp that is killed by cultivation.

Back to butterflies and moths

Cabbage White Butterfly

The cabbage white butterfly is a European import. It first appeared in Australia in 1939, and soon became a major pest of all cabbage crops, as well as wallflowers, stocks, occasionally mignonette and nasturtiums and a range of weeds like wild mustard.

In warm areas cabbage White butterfly larvae will feed throughout winter. In colder areas they do most damage in autumn and spring.

Cabbage White Butterfly

It is the larvae of the cabbage white butterflies that eat the leaves. The butterflies themselves feed on nectar, usually from flowers, though I have seen them on gum trees as well. The butterflies are a creamish yellow with black wing tips, and a black spot on the hindwing, about 5 cm across. The female has two black forewing spots, while the male has only one.

Cabbage white eggs are a pale yellow, and laid on the underside of leaves, usually near the edge. The young caterpillars hatch there and start feeding under the leaves, transferring up top as they get older. The young caterpillars are pale green with fine velvet hair and faint yellow stripes down the side. They usually feed for two or three weeks before pupating, and there may be several generations a year.

Cabbage white cocoons are light greyish yellow to green and about 18 cm long. In cold areas the cabbage whites overwinter in their cocoons, either attached to growing crops or just nearby, and it can be worth white hunting these out and destroying them, though the butterflies can fly several kilometres, and any susceptible crop is likely to be attacked.

Predators

These include three imported wasps that attack the caterpillars. I have also noted several native wasps carrying off caterpillars and a wide variety of birds, as well as assassin bugs, mantids, centipedes, dragonflies, ichneumons, scorpion flies and spiders. Lacewings eat caterpillar eggs and hoverflies may eat very small caterpillars just after they have hatched. There is also a natural virus that may reduce numbers.

In a diverse garden you may find that natural predators are enough to control the caterpillars – but only after a wait of several weeks while they notice the available food. There may be considerable damage during this time. Choose a means of control that won’t deter the predators — like squashing the caterpillars on the leaves, or using D1PEL. The latter will still leave edible caterpillars – and while sickening they will be easier to catch. Like all of us, predators are attracted by an easy food supply.

Control

. place empty egg shells in the beds to outfox the butterflies as to their population density: (I’ve tried this in three control plots over three years – it worked only once); . surround the beds and PROFUSELY interplant with strongly perfumed herbs like lavender, marigolds, and nasturtiums. This works best combined with the other disguise technique below;

. interplant other crops so it is more difficult for caterpillars to migrate from plant to plant, and so the pests find it harder to recognise the brassica silhouette (see above). The more ‘companion plants’ the less damage.

Sprays and dusts

Make sure that you spray or dust the undersides of leaves as well as tops, as this is where the young caterpillars will be hiding.

Try flour first. This is a caterpillar stomach poison. It will take three or four days to be effective, however, and may be washed off before enough is eaten.

Mix flour and boiling water to a bill stickers paste, then add more water and spay that. Glued up bugs stop eating – and are easy for predators to find.

Try DIPEL as the next resort, or clay spray (this is just clay and water – no dirt, though), bug juice or white pepper spray. (White pepper spray will slightly dehydrate the caterpillars. Most will die; the rest will be easy prey for birds etc).

You might also try dusting the leaves with powdered rock phosphate for the same effect. If these fail try wormwood spray, garlic. quassia, or dusting or spraying with derris. These are all last resorts, though, as they all kill non target species.

Caterpillar trap

This may be useful for large infestations where caterpillars denude one plant then move on to the next. Place a small three sided box at the base of plants – about 10 mm high. Place a scatter or lime or wood ash inside. The caterpillars should shelter there during the day, and dehydrate. A scatter of wood ash around plants also stops migration..

Cabbage Moth

While the cabbage moth is quite different from the cabbage white butterfly – it’s greyish brown and hairy with yellow diamond shaped markings when the wings are folded – the caterpillars of both are easily confused. Both are green, and both devastate cabbages, cauliflowers and similar crops. Cabbage moth caterpillars however are a clearer green than cabbage white caterpillars and lack the velvety appearance and yellow stripe.

In terms of garden control however the difference is slight. Cabbage moths also lay their eggs on the underside of leaves. The cabbage moth caterpillar tends to eat towards the heart of the vegetable, and may cause even more damage than the cabbage white.

Predators

Like cabbage whites, the cabbage moth caterpillars are preyed upon by a range of imported wasps — different ones from the cabbage white’s. Native wasps don’t appear to be so particular, and I have noticed two species here that will carry off either. The same range of birds also appears to attack both.

Cabbages as herbicides

Brassicas going to seed inhibit the germination of seeds around them, and the growth of other plants. I make use of this by letting a plot of brassicas go to seed in spring – then hauling them out two months later. The result is a nearly weed free bed for early summer planting – and the massive roots have ‘dug’ the soil.

The above may all sound complicated. In reality, if you have good soil and good cultivation practice, the only trick with brassicas is to know when to plant them – and what varieties suit your area and the time of year you want to plant. That’s mostly a matter of peering over your neighbours’ shoulders and seeing what works for them and looking through seed catalogues for appropriate varieties, rather than choosing the mass-produced seedlings so often sold by nurseries, that are almost suitable for most areas – but really suitable for none.  

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