I want to write about cabbages today, as it seems I’m not the only one sometimes struggling with these. But there are plenty of solutions! The brassica-family consists of cabbages (red, green, savoy, chinese…), kale, cavolo nero, broccoli, cauliflower, brussel sprouts, mustard, radishes, mizuna, mibuna and some other asian salad greens. Except from radishes which grow really fast, they all have very similar patterns and succumb to the same problems: porr nutrients, caterpillars, aphids and bolting.
First of all, I’ve given up growing them over summer. The white butterflies are omnipresent, and lay their eggs on the leaves faster than I can keep them away. But in January, I start seeds. I prick them out into 15cm deep boxes, at 5cm distance from eachother, and then leave them there until they’re big and sturdy. While they’re in the boxes, it’s much easier to protect them from the butterflies – either using netting or bt-spray or both!
If you choose netting, use a fine mesh so the smaller butterflies can’t get through. Microklima cloth is also a good solution. For the spray, I buy a certified organic one at Commonsense Organics called Caterpillar Control (KiwiCare brand). It contains bacillus thuringensis, which infects the caterpillars. It seems to work really well, as long as you keep on top of it. You need to spray once a week or at least every 10 days.
For soil preparation, I’ve had best results in beds with bokashi dug into the soil. I also use a good calcium, Dalton’s Clay Breaker or Environmental Fertilisers’ NanoCal or MultiCal. I dig the soil over to make sure it’s open and drains well, as my clay soil tends to be waterlogged in winter.
Planting out, I plant them deep. Soil level can be at the first pair of true leaves. And I tamp them down well, so the soil is firm around the roots. Water in, and then use a liquid fertiliser at least once a month, better still a little once a week. They still need to be protected from the caterpillars even when they’re in the bed, but I prefer broadcast sow dill and/or nasturtiums underneath as companions and use a netting over, rather than continuing with the sprays.
As they grow, you can start eating the lower leaves. Take them before they go yellow, but not too early either as the plant needs them to photosynthesize. All leaves from all cabbages are edible, even though the supermarkets only sell the “final product”! So instead of letting these leaves fall off and feed your slug and snail populations, why not harvest them for yourself?
The ones I’ve had most success with were Red Russian kale and Green Curly. Purple Sprouting Broccoli also yield well – at least if you also eat the leaves. But cauliflowers, heading broccoli and chinese cabbages have been constant disappontments… They take up a lot of space in a small urban garden and you wait and wait for the final result, so it’s quite frustrating when you only get a fist-sized end product. If you’re just starting out, go for Red Russian. Nice flavour, pretty in the garden, long and abundant yield and you can see the bright green caterpillars against the purple leaves. Steamed or stir-fried they’re delicious, or as a ferment with dill and carrots. Even in salad, with some nasturtium flowers and some dill leaves, as these companion plants are also friends in the salad bowl.