Top tips to grow cabbage
Author: Met Pember
Photography: Chris Court
Pictured above: pork and cabbage pot-stickers.
One of our most versatile vegetables, cabbage can be eaten raw, steamed, fermented, pickled and barbecued. In Italian the word for cabbage is cavolo, which is also used as swear word, once again demonstrating the versatility of this robust brassica.
But just as it feeds us, cabbage makes demands of its own. As with all brassicas in the vegetable patch, it's a constant battle to keep up nutrition supplies for this hungry feeder, while also keeping away the hordes of cabbage white butterflies that call this vegetable their own.
April is the perfect time to plant cabbages as young seedlings; it's not too late, however, to start propagating them from seed. Begin by planting seeds in a tray at no more than one centimetre deep, and keep them well hydrated until they germinate, which occurs within anywhere from 10 days to three weeks. Incubating your seed tray in a mini greenhouse will reduce evaporation and therefore accelerate growth. If your mini greenhouse is portable, move it out of direct sunlight on hot autumn days, then put it outside in the cool of the night. Cabbage is a cool-season vegetable and favours a soil temperature of 15 to 18 degrees. Letting it find its comfort zone will have it up and about earlier.
Once the seedlings are three to four weeks old they're ready to be transplanted into the patch. Choose a sunny spot - although they will also tolerate part shade - and ensure the soil is well boosted with compost and nitrogen-rich fertiliser. If possible, plant the seedlings where you have just harvested your beans, but try to avoid planting where other nitrogen-hungry spring crops have been depleting the soil - tomatoes and corn in particular.
When you plant out the seedlings, set up netting to protect them from their namesake nemesis, the cabbage white butterfly. Of course, it's not the butterfly itself that causes the damage; rather it's the almost invisible green caterpillars that hatch from their larvae. Within days, an entire crop can be devastated as the almost invisible green caterpillars grow fatter and somewhat less invisible feasting on the brassicas. Well-constructed netting prevents the butterflies from landing and laying their larvae.
Water the seedlings daily for the first month and mulch with three to five centimetres of lucerne hay or pea straw. This not only helps lock in the soil temperature and reduce evaporation, but also provides nutrition as it breaks down. As the weather cools and your cabbages settle in for winter, you can cut back to two to three waterings a week. Keep track of any invaders. Snails and slugs can be active now, particularly if the weather becomes wet, but the main duty is to check on the plants and give them a monthly tonic of liquid seaweed. This will keep their demand for nutrition satisfied.
After three to four months, as spring arrives, the cabbages will be approaching readiness. This is a one-head, one-harvest kind of crop, so remove all remnants of the plant after harvesting, which allows the soil to recover sooner. Be sure to inspect the heads for rogue slugs and caterpillars, and wash them well before eating.
Deciding what to do with the produce is like having a dollar in a lolly shop, circa 1990 - there is so much choice. We like to use the outer leaves for pork rolls stewed in ragù, and the denser heads for coleslaw or sauerkraut.
TIP OF THE MONTH: COOLING SOIL FOR AUTUMN PLANTING
At this time of the year gardeners often talk about soil temperature as though they're baking bread. To give this some context, it's the soil temperature rather than air temperature that dictates the growth of our plants. Cool-season varieties need the soil to be around 18 degrees - the perfect temperature to start "baking" cool-season crops.
While we can't alter the air temperature, there are ways to accelerate the cooling process. Removing mulch from the patch as the weather chills down will expose the soil to cooler air, like taking off the blanket in bed. And with the soil now exposed, it can cool down more quickly to the ideal planting conditions.
Rather than licking a finger and burying it into the dirt there are more scientific instruments, such as soil thermometers, that take a more accurate temperature reading. When the soil is approaching 18 degrees, lock in the temperature by replacing the blanket of mulch. Now you've achieved autumn planting perfection.