Unlike the loose and tender heads produced by summer cabbages, winter cabbages are much larger and denser, thanks to their longer growing season. While this does mean that their leaves aren’t quite as juicy as their summer alternatives, they make up for this by being cold-hardy enough to feed you until the start of spring.
Growing Winter Cabbages: A Quick Snapshot
When to Sow – Apr-Jun
When to Plant – Jun-Jul
When to Harvest – Nov-Mar
Average Yield per Plant – 500-1000g
Spacing – 45cm
Depth – 0.5cm
How to Grow Winter Cabbages at Home
Although extremely hardy, winter cabbages, just like any other plant, still need light to grow. This is in short supply over the winter, making it important to start your seeds at the right time to ensure that your young plants are able to make the most of all of that mid-summer light.
In addition to getting your timings right, there are also a few basic growing requirements that you’ll need to meet if you want to harvest large and heavy cabbage heads.
Growing Requirements for Winter Cabbages
Both summer and winter cabbages do best when they receive full sun. This is easier with summer cabbages, as even a spot that’s partially shaded in the afternoons will still likely provide enough light during the rest of the day. However, with light being so limited from autumn onwards, make sure that you choose a site that receives all-day sun for your winter cabbages.
In terms of soil, you want this to be relatively firm but well-draining. The well-draining part is especially important – this is what will prevent any ice from damaging your winter cabbage roots.
Incorporating compost or rotted animal manure is a good way to increase soil fertility. Add this into your growing area when you sow your seeds indoors, so that it’s ready for your seedlings when you come to plant them out.
It’s also worth keeping in mind that cabbages prefer a slightly alkaline soil. That said, they’ll tolerate neutral and slightly acidic soils too, although this may mean smaller heads at harvest time.
How to Grow Winter Cabbages from Seed
As mentioned, you’ll need to time things correctly if you want to give your cabbages enough light to mature. Sow your seeds too late and your harvest will be small, but sow them too early and they won’t last the winter.
Ideally, aim to sow your winter cabbage seeds about three months before day length drops down to ten hours or less. This will give your plants just the right amount of light to mature before the days get too short.
Since winter cabbages are sown towards at the end of spring/early summer, starting your seeds off indoors isn’t strictly necessary. While this will give you a more uniform crop size, while also protecting seedlings from pests, those who are looking for a lower-maintenance way to grow can easily direct sow their seeds instead.
Water your trays well, making sure that excess water drains freely from the bottom. Cabbage seedlings hate to have wet feet, so drainage is important
Make a small indentation in the centre of each module, about 0.5cm deep
Place two seeds into each indentation and cover back over with soil
Water lightly again and then place your trays somewhere warm. 25°C is the optimal germination temperature, making a heated propagator ideal
At this temperature, it should take about a week for your cabbage seeds to germinate.
Once they do, give them a week to grow before snipping away the weaker seedling from each module. Make sure that your seedlings are getting plenty of light and enough water. You’ll need to continue growing them on indoors for at least a month before they’ll be ready to move out. If necessary, transplant them into larger pots before planting them out.
How to Direct Sow Winter Cabbage Seeds:
Prepare your growing area by thoroughly weeding it and amending the soil if necessary
Create shallow furrows in the ground, about 0.5cm deep
Sow your seeds. You’ll need a final spacing of around 45cm, but you can always thin out any extra seedlings later on
Cover the seeds over with soil and then water your growing area if it was dry
How to Plant Winter Cabbages Outside
Once your winter cabbage seedlings are ready to move outside, you’ll need to harden them off for about a week. Since you’ll now be in mid-summer, meaning that outdoor temperatures won’t be too different from indoor temperatures, the hardening off process is much faster.
Dig small holes in the ground, just slightly larger than the root ball of each of your seedlings. Remove your seedlings from their modules and place them into their new homes. Aim for the lowest leaves on each seedling to be at ground level. Cover the roots over with soil and then firm this down around them. Cabbages do best in firmer soil.
Water your plants well, ensuring that the water is soaking the roots too.
You’ll now need to set up some form of sun protection for your winter cabbages. While the plants do need plenty of sun, they’re still quite delicate when young. Intense summer sunlight will quickly scorch cabbage seedlings, but row covers are an easy way to prevent this. These will also give your plants some extra protection when temperatures start to drop.
How to Plant Winter Cabbages in a Greenhouse
Winter cabbages are a great crop to grow in a greenhouse. The extra warmth that a greenhouse provides will extend your growing season in the winter, while also making it easier to harvest each cabbage since the ground won’t be frozen.
Use the same planting methods as when growing winter cabbages outside. The only difference is that you’ll need to make sure that your seedlings don’t overheat. Plenty of ventilation is also important.
Of course, winter cabbages do grow quite large. If you don’t have enough space in your greenhouse beds for more than a couple of cabbages, consider growing some in containers too. This will allow you to keep them outside during the summer, before bringing them into your greenhouse in the autumn when your other summer crops have died back.
So long as you pick a deep container, you should still end up with a decent harvest, although the heads won’t be quite as large as those grown in the ground. Don’t attempt to use grow bags instead of containers, as these don’t provide enough space.
How to Care for Winter Cabbages
The care that you’ll need to give your winter cabbages is similar to how you would look after spring and summer cabbages. However, the winter elements do pose more of a challenge, so you may need to give your plants a little extra attention…
Watering Winter Cabbages
While spring and summer cabbages require a fair bit of manual watering, winter cabbages aren’t quite so demanding. The weather tends to already be much wetter in the winter, so you’ll likely find that rainfall will provide the 3cm of water that your cabbages need each week.
If you do happen to experience a dry spell, then give your winter cabbages some extra water. Try to do this late morning, so that the water has enough time to soak into the ground before temperatures drop again, which would cause it to freeze on the surface.
Feeding Winter Cabbages
Cabbages need plenty of nitrogen in order to properly grow. This is usually readily present in the soil during the warmer months of the year. However, as the rain increases in the winter, soil nitrogen ends up washed away, which will leave your plants lacking.
This makes a nitrogen-rich fertiliser important. Give your plants one dose soon after planting them out. Then, feed them again six weeks later, and then once more after another six weeks. This should give them all that they need to produce large and firm heads.
Weeding and Mulching Winter Cabbages
While weeds may be a nuisance when you first plant your winter cabbages out, they’ll soon die down as the colder temperatures arrive. This means that you’ll only need to really weed your growing area while your plants are young – after this, they’ll be able to fend for themselves.
So, while mulching to keep the weeds away isn’t quite so important, it’s still worth considering using a mulch to help regulate soil temperatures. Applying your mulch while the weather is still warm will help to trap this heat into the soil, keeping your cabbages a little warmer through the winter.
Winter cabbages are extremely hardy, but this doesn’t mean that they won’t struggle if you experience a colder-than-average winter. With climate change causing weather patterns to fluctuate quite wildly, it’s always better to be prepared.
So, with that in mind, put together a plan for giving your cabbages some extra protection if temperatures drop to lower than what your variety can tolerate. If you already had row covers in place to prevent sun scorch, then this should be sufficient for cold protection. Alternatively, look into a more heavyweight cover, or even a cold frame or low tunnel.
How to Harvest Winter Cabbages
Once your cabbages have produced firm heads, they’re ready to be picked. However, don’t be in a hurry to harvest them all at once – they’ll be fine in the ground for a couple of months. This way, you can harvest them as needed throughout the winter.
To harvest a cabbage, use a sharp knife to cut the head off at ground level. Take some stem with you but leave the roots in the ground. If you’re lucky, the remnants of the plant will produce a few mini cabbage heads once the weather warms up.
How to Store Winter Cabbages
Cabbages are known for storing well. When kept in the fridge, a cabbage will last for over a week. Alternatively, store your harvest in a root cellar and the heads will keep for about three months. If you don’t have a root cellar, a cool, dry, and well-ventilated environment will work instead.
If you plan on storing your cabbages long-term, then leave the heads unwashed. Don’t trim off any outer leaves either. Wait until you’re ready to use your cabbages before doing so.
How to Prepare & Cook Winter Cabbages
To start with, you’ll need to peel off any tough or damaged outer leaves. Don’t panic if it looks as though the frost has gotten to your cabbages – peel off a couple of layers and you’ll find that the leaves within are healthy and untouched.
Then, rinse the cabbage head, slice the cabbage in half, and cut out the hard interior core. Your cabbage is then ready to be sliced, chopped, or shredded as needed.
Cabbages are a star ingredient in many dishes from all over the world. While you can keep things simple and just boil, steam, or stir fry your harvest, try experimenting with some of the following warming winter dishes:
Lemon cabbage pasta
Common Winter Cabbage Problems
Other than the cold, a few of the issues that you may experience when growing winter cabbages are:
Bacterial leaf spot – this bacteria causes dark spots to form on cabbage leaves. These will increase in size as time goes by, soon killing off the foliage. It’s spread through water splashes, making it prevalent in wet winters. Try to protect your foliage from excess water to curb the infection, and don’t grow any brassicas in that area for the next few seasons
Downy mildew – a common disease in wet and mild winters, this one causes white/grey fungal spores to appear on leaves. Improving air circulation helps, but serious infections may need to be treated with a fungicide. If your plants are too far gone, then you won’t be able to eat them
Root rot – poor drainage and excess water contribute to root rot. You’ll first notice discolouration on the leaves, and by the time you realise that root rot is the cause, it may be too late. Improving drainage is a must, and a copper sulfate soil treatment can help to prevent the disease from spreading
Popular Winter Cabbage Varieties to Grow
When choosing winter cabbage varieties, opt for those that are as cold-hardy as possible. Some of the best options are:
Brunswick – a year-round heirloom variety with tight heads. This one is cold-hardy and good for storage
Tundra – fast to mature with dark green leaves and tight heads. This hybrid variety sits somewhere between a savoy and a white cabbage, making it very cold-hardy
January King – a very sweet-tasting cold-hardy variety that also looks gorgeous with its large green/purple crinkled leaves
Late Flat Dutch – loved for its absolutely massive heads, although these large plants do require more growing space than other varieties
Savoy Perfection – a classic savoy-type that does well in cold winters
If you’ve already grown spring or summer cabbages, then winter cabbages aren’t too different. Granted, you’ll need to take the cold into consideration, but, so long as you pick the right varieties and give them a basic level of care, you should end up with plenty of large cabbage heads to feed you right through until spring.
Alina Jumabhoy has spent several years learning about, and experimenting with, different organic growing techniques at various gardens and farms around the country. Fuelled by her quest for self-sufficiency, she’s now putting that information to good use on her own rural farm.