Brassica oleracea, var. Capitata
This lesson concentrates on the ‘central’ part of the cabbage family, the ‘Capitata’ heading cabbage. In English, the heads are also called hearts.
Heads and leaves
Heads can develop from spring right through to autumn, and in winter for Savoy cabbage. They originated in the Savoy region of 16th century France, and have their own genetic group called Sabauda.
- Kale is closely related to cabbage, as shown by ‘tree cabbage’, whose harvest is leaves; this illustrates one of many possibilities in this huge plant family.
Spring cabbages can either be heads, or leafy plants. There are varieties bred to grow only tender leaves, sometimes called spring greens. They include Greensleeves and Wintergreen Improved. You could also pick outer leaves of cabbage to eat, but this would delay and reduce the heading process.
Cabbage is biennial and, if heads are not cut in autumn, plants will make flower heads from them the following spring. Flowering may also happen in summer, from very early plantings sown in late winter, when their heads are left unpicked.
- Days from seed to first harvest: 80–220, depending on variety and time of year.
Cabbage seeds sownCabbage ready to harvestLate winter to early springLate spring to early summerLate springAutumnMidsummerWinter to early springLate summerMid to late spring
- Best climate is temperate, moist; winter may be cool but summer not too hot.
It’s possible to cut a cabbage almost any month of the year in temperate climates.
- Cabbage for white heads, sown mid-February to mid-March, is ready from June to July.
- Cabbage for red and white heads, sown early May, is ready from September to November.
- Cabbage Savoy, sown by late June, is ready from December to March.
- Cabbage, spring-sown mid to late August, is ready from April to May.
You can certainly eat cabbage all year. Heads of cabbage make wonderful pickles such as kimchi and sauerkraut, and they keep well too, especially in winter months.
Why grow them
Cabbage is luxury food! It’s also easy to grow, as long as you are in control of potential pests.
You can have a range of harvests over long periods. Homegrown cabbage, when no synthetic fertiliser is used, is tender and full of fine flavour.
There are also the wonderful microbes when soil is healthy. These are good for you in coleslaw and help in pickling. The sauerkraut recipe we use is very simple:
- Chop cabbage finely, even in quite long lengths if you wish.
- Pack into a clean jar and cover with water, which has added salt in the proportion of 30 g/0.5 oz per litre.
- Best result is from having a sealed lid and from placing a larger cabbage leaf on top of the cut cabbage, to keep the latter below the level of liquid.
- You notice a bubbling for two to three weeks, and then the pickled leaves are good to eat, full of flavour and with good microbial quality.
Suitable for containers/shade?
Cabbage can grow in shade.
For container growing, choose small varieties like the spring cabbages below. Even though they are called ‘spring cabbage’, you can sow them in summer for harvest in autumn – a top variety is Duncan F1, for pointed heads.
Below are the four seasons of potential harvests, and information on which varieties give the finest and biggest harvests at each time.
In temperate regions, you can sow cabbages for spring either in late summer or late winter, and the varieties below are possible at either time. In cold climates, it’s best to sow these in early spring because they might perish in winter – try it once to see.
Advantage, Cape Horn, Caraflex and many others are good. They are all F1 and grow pointed heads of low weight, usually under 1 kg/2.2 lb.
I used to grow the open-pollinated Greyhound until it declined in quality, as you can see the photos below.
These varieties are for sowing in late winter to early spring, and they need longer to mature compared to spring cabbage. One nice result is that the heads are often heavier.
Their speed of growth also means that heads do not stand very long before splitting. You can cut them when pale and firm to convert to pickle, or store for up to a month. Either way, you free up the ground for more plantings.
Cabbice, Kalibro, Stonehead are all F1 and make pale green, round heads of medium to heavy weight. The Cabbice below had fleece over for four to five weeks, after being transplanted in late March.
These are for harvest in autumn and can also be stored through winter, as long as they make firm heads. Filderkraut heads are impressively tight, while the San Michele is looser and more green – nice for eating fresh, see below.
Filderkraut makes a heavy pointed head of up to 5 kg/11 lb, Granat makes a smaller but dense round head up to 3.5 kg/7.7 lb, while Tundra F1’s head is more savoyed and less dense. The white stems are delicious raw, just trim off the fibrous outer layer before eating.
- In my Three-Strip Trial, Granat gave 19.25 kg/42.4 lb of trimmed heads from nine cabbage = 2.1 kg/4.6 lb each
- Filderkraut gave 38.46 kg/84.8 lb from nine cabbage = 4.3 kg/9.5 lb each
Mostly these are the Savoy type. Their crinkled leaves keep more air in the heads, allowing expansion of ice when they freeze, rather than heads splitting.
There are also autumn-heading Savoy varieties, so check the description every time. It helps when you know what to expect.
Paresa, Wirosa, Wintessa are all F1 and mature in winter, from June sowing.
To sum up a little:
- Each variety has a best sowing date for biggest harvest.
- The date of harvest depends mainly on variety, but also on the sowing date. You can vary the sowing date for any one variety, to make its harvests a little earlier or later.
Two examples :
- Cabbice’s best season to grow before heading is spring, for heavy heads by midsummer. Sow Cabbice in February for an early July harvest of heavy heads. If you sow Cabbice in June, the October harvest is of lighter heads.
- Filderkraut heads up most strongly in autumn. Sow in early May for heavy heads by October. Alternatively, sow in early June for lighter heads by late October to November.
Sowing methods are the same in all seasons, and are under cover for best results. You can transplant cabbage at almost any size, from four to eight weeks old.
- Seeds germinate within three days, with large cotyledons in five to seven days.
Sowing conditions and method
Germination and growth can be in temperatures as low as 10 °C/50 °F but are healthier at 15 °C/60 °F or higher.
You want one plant per module, so either sow in a tray to prick out, or sow two seeds per module and thin to one.
This is according to the variety you are growing – follow the dates I give above, under ‘Harvest period’, as a guide. These dates are a broad outline and you can use them to discover the absolute best dates for your climate.
My own three sowing dates are:
- Late February with warmth, for harvests in May to early July.
- Early May, for autumn harvests.
- Late August, for harvests in early spring.
This is a useful option if the bed space you want to plant in is still growing a preceding vegetable. You can raise cabbage plants in many ways, and transplant at many sizes.
It used to be that farmers transplanted cabbage from large and bare-rooted plants, carried in sacks on their backs. They did the planting almost at walking speed, using a mattock to create a diagonal slit in the soil just ahead of their feet. The cabbage plant was pushed firmly into that slit then walked on, and they moved forwards.
This is less appropriate to gardens but is useful knowledge, illustrating that:
- Cabbage plants are tough.
- They can go quite deep into firm ground.
A benefit of no dig is that soil is firm already, so there is no special bed preparation. For example to clear preceding broad beans, simply cut out the central large roots to detach the bean stems. Then lightly rake level before planting cabbage. I emphasise the phrase ‘lightly rake’, after noticing that gardeners often pull it too deep. Just skim the surface to even it out – it should be almost effortless (see my Tools and Techniques video on YouTube.)
As for many brassicas, a plant height of 10–15 cm/4–6 in is good, according to conditions and when the ground is ready. An exception is to use small plants in autumn for spring cabbage, because:
- If sown too early, they risk maturing before winter and then won’t crop in spring.
- If transplanted too late, they won’t have time for roots to establish before winter.
Best sowing date for spring cabbage here is late August, from which it works best to plant four-week-old plants in late September, rather than six-week-old ones in mid-October.
As with sowing dates, this varies according to the type of cabbage you are growing. It will be from early spring to early autumn, and from four to six weeks after you sowed.
Interplanting must allow for the need of protection at transplanting time: is a cover appropriate for the other vegetable? You could transplant autumn cabbage into a bed of spring carrots, as I do with Brussels sprouts. You may be able to work out other combinations which fit your harvest timings.
The rule of thumb is wider spacings for larger heads. However, most spring cabbage varieties do not make large heads because they are ‘programmed’ to mature quickly. Hence the best spacing for them is 25–30 cm/10–12 in.
For summer cabbage, the range is 35–40 cm/14–16 inches, and for large heads in autumn you can go as wide as 60 cm/24 in. The red cabbage in these photos are spaced at 45 cm/18 in and they grew heads of a decent size, around 2 kg/4.4 lb.
They were a second planting after the broad bean harvest, and we gave no feed or new compost. There is no time for that in summer, nor clearly is there any need.
Support is not needed for cabbage plants.
Summer cabbage, in particular, need watering regularly for a week or so after transplanting. As usual, it’s a question of watching the weather and your soil condition.
The best stage of life for efficient watering is when plants are heading, but only if soil is dry. Under-watering can stop the head from fully developing. However, if you overwater a cabbage whose head is already tending to the firm stage, you risk causing it to split.
Close spacings need more water, but cabbages need rather less than Brussels sprouts and broccoli because they are mostly smaller plants.
Extra mulch to retain moisture?
Always an option for dry climates, but this is rarely of great benefit to cabbage because of how quickly the ground is covered by their leaves – see the next section.
How to judge readiness
Heads taste good at any stage, even before they are tight. Sweetness increases as they firm up, from there being a high proportion of pale, blanched leaves.
Each variety has a slightly different habit and firmness of head, while this also varies according to the time of year. I love Savoy cabbage for their sweet heads in late winter, when green leaves can be scarce. Then, from spring to early summer, it’s rare that any head is large or very firm.
How to pick
The best tool is a sharp and strong knife, because to harvest a head you are cutting across strong fibres of the main stem. Cut at the level between nice-looking leaves above, and old or damaged leaves below.
When to pick and how often
Once a head has been cut and removed, the cabbage stem will grow a few very small and open secondary heads. For the time and space needed, they are rarely worthwhile. I clear stems after cutting the main head.
Firm heads of cabbage store impressively well, as long as the temperature is below 10 °C/50 °F – cooler is better. Winter cabbage heads are best cut and stored in a shed, although they do stand frosts of about -5 °C/ 23 °F.
Which pests are likely, and when
There are only small differences, compared to other brassicas.
- Flea beetles are not usually too much of a problem.
- The maggots of cabbage root flies cause damage from late spring through summer.
- Rabbits can cause new plantings to ‘disappear’ overnight, unless protected.
- Caterpillars arrive by midsummer and eat a lot for the next three months. Heads need protecting, because one caterpillar can damage so many leaves when eating into it.
- Pigeons risk killing plants at any time of year, depending on where you are.
These are the same as for broccoli (Lesson 5): netting for rabbits and pigeons, and mesh for insects. Also, Bacillus thuringiensis spray for larger plants, when mesh is not possible.
Other likely difficulties
Clubroot is the main disease problem, but it’s relatively rare. Spores are most active in warm soil, with less damage to winter brassicas such as spring cabbage, whose growth is mostly in the winter months.
Clubroot results in galls or swellings, on roots and lower stems. These impede the uptake of nutrients and water.
It is spread through any import of infected plants, or from infected neighbouring plants, by use of infected tools, moving infected soil and even from surface water runoff. Spores remain dormant for several years, until coming to life again on host plants.
- You may discover resistant varieties for sale – worth a try but no guarantee.
- Clubroot thrives in slightly acid and wet soils, while no dig reduces the incidence. Worth spreading a little lime in spring every year, to lessen the damage.
Heads fail to grow large and firm
Here are some reasons why they may not fold in tightly:
- For autumn cabbage, there was insufficient growing time between sowing and winter arriving. (This does not apply to cabbage for spring heading.)
- The variety was the wrong one for the time of year you grew it in.
- You had not noticed that the variety was one for fast growth and small heads.
- Lack of soil fertility: large heads grow in rich and firm soil, capped with a compost mulch.
- Possibly the variety itself was to blame, from its seed being poorly maintained by a seed company.
When I am harvesting, I also carry a bucket for waste, weeds and diseased materials, which will then go on the compost heap. This means that, when harvesting cabbage for example, as soon as it has been cut I twist the stem to remove it.
You can even stand with your two feet on the soil around the base of a stem as you twist, in order to less disturb the soil. The result is that only a few roots are left on the stem, with most of them in the soil.
Before throwing a stem on the compost heap, cut it lengthways into two or four thin lengths in order to speed its decomposition. You could halve these with the knife, since their reduced diameter makes that possible.
This depends on when you cleared the cabbage.
Check my Sowing Timeline for possible new plantings. There is also a southern hemisphere version available on that page. Some examples include:
- Sow carrots or transplant beetroot after spring cabbage.
- Transplant leeks or chard after summer cabbage.
- Sow garlic or transplant broad beans after autumn cabbage.
Grow anything after winter cabbage, except perhaps more brassicas. Or you could transplant salad onions, and then follow them with more Savoy cabbage for winter. I have done that.