When you think of kitchen gardens you think of cabbages, well maybe other things as well but certainly there is a row or two of some sort of brassica in every productive plot almost anywhere in the world. Which is not bad going for a humble weed found eking a living on the chalk cliffs of Dover. You can still see a few fairly true specimens though other related crops such as oil seed rape are starting to confuse the population. There are several other wild brassicas contributing to our modern hybrids' genes but the bulk come from those wild coleworts, coles or collards as thet've been called.
Well known to the Romans the early coles were somewhat loose and flabby but considered to be near miraculous at curing many diseases. Apparently somewhat unhappy about the disastrous success rate of their 'doctors' the Romans restricted them to first aid and forbade the offering of any curative potions etc. other than cabbage! Well as in those times the bulk of diseases were probably either malnutrition or aggravated by it then a dose of cabbage would likely work wonders! Certainly I have found that either cabbage or even better fresh raw cabbage leaves expressed as juice do act like an amazing tonic inside or out. (Mind you it sure proves the old saw about it don't do you good if it don't taste horrid!).
The Ancients selected from the wild populations found all round European coasts and bred these to separate lines that became our summer cabbages, the forerunners of the Savoy's with crinkly leaves, kales and the earliest sorts of cauliflower and broccoli. During the dark ages we continued with these forms while other hardier strains from central Europe slowly intermixed and enabled the crops to survive harsher conditions. Unfortunately the seed production was not controlled and resulted in many mongrel crops. Amazingly somehow the various forms remained distinct and slowly improved. Relatively recently between the late middle ages and the Renaissance the sprouts were developed, apocryphally, in Brussels! Likewise Calabrese came from Italy, and from Portugal we got Couve tronchuda which is a cole developed for it's swollen leaf stalks.
Almost every part of the cole has been selected for and improved. As just mentioned; in the Portuguese cabbage it's the leaf stems, in the kales it's the leaves and in rapidly cropping dwarf forms the immature leaves. In the cabbage it's an enormous swollen terminal growth bud, in the cauliflower an enormous terminal flower bud. In sprouts it's swollen growth buds in the axils of the leaves and in sprouting broccoli's it's swollen flower buds and shoots from the axils of the leaves. The kohl rabi is a grossly swollen 'cabbage' stem, some folks also like to crack and eat the crunchy pith inside other brassica stalks. In the Jersey walking stick cabbage the stem has become elongated to more than a couple of metres so the leaves can be plucked successionally for animal fodder.
The turnip is a close relation as is the Swede which are both effectively swollen cabbage roots. Commercially we grow oil seed rape which is also very closely related and used for the edible oil (called Colza in some countries). Almost identical is mustard too well known for description as a seed crop for condiment and as the cotyledon leaves eaten after sprouting on a piece of flannel. From China we get a parallel series of brassicas developed from their wild mustards. Pe-tsai, Chinese cabbage, more closely resembles a Cos lettuce than a European cabbage and it's sister Pak-choi resembles a chard more than the Portuguese cabbage it duplicates. These brassicas are of much more rapid growth than our forms -and are also the most slug palatable plants I've yet found.
Then of course there we have red versions of cabbage, cauliflower, broccoli and Brussel's sprouts which I rather like and I find these often avoid pest attacks. There are green cauliflower/broccoli's such as the divine Romanesco and miniature caulis with heads no bigger than tennis balls -but with wonderful texture. We have round headed and pointed, winter and summer, loose and firm cabbages of every shade, texture and hue including those really nasty ornamental sorts. I'd sentence garden designers who claim these last as edible to a diet of them! And all of these from a few ancestors.
Minicole, a modern reintroduction, closely resembles the earlier coles and I've found it robust and easy to grow if not startling in size or density. The most modern brassica varieties give staggeringly good performance in good conditions but have lost a bit of that earlier robustness! I grow large numbers of varieties in trials and it is notable how some are always better or worse, or more or less attacked than others. It is not expensive to buy a load of varieties in one group, say caulis, or sprouts, and grow a couple of plants of each in comparison -if you can find the space. It is a relief, and a problem, to see how in any trial success or failure of any one variety seems to be due entirely to the year -which bizarrely also suits another variety just fine. And of course it is impossible to predict which will do best beforehand, though naturally we all select for success rather than failure afterwards. Do try as many as you can, I bet you'll find at least one or two sorts that suit your conditions more than your current varieties.
Along with a vast number of cultivars there are a vast number of pests and diseases associated with the brassicas. This is because they have native relations and because they have been grown in such quantities for so long. I doubt there is a plot in the country that has never raised a cabbage of some sort at some time, if not every year since Caesar ruled! However nature being so cunning at filling niches has had time to create a whole number of predators and parasites to help control that legion of pests. I practice no active small pest control at all on my brassicas (I'll deal with pigeons in a future article!) and I rarely find crops damaged to the point of total loss though sometimes there is considerable cosmetic damage. However this does not bother me as with say a dozen different varieties on a bed, more than I need is available from the best which will have taken over and those that did poorly would be surplus anyway.
My soil is very light and dries out rapidly and being full of silt and sand with little lime or clay does not really suit brassicas. This combined with being situated in East Anglia with drought levels of rain means that I have to do a good job to ensure any success at all, especially with caulis which are most demanding of all. I enrich the planting holes with sieved garden compost and calcified seaweed to provide lime but do not normally use any other fertiliser apart from a drop of liquid feed in the early waterings and foliar sprays of seaweed solution once a month. Brassicas are well known for needing lime but they also need quite a lot of sulphur, and phosphorous which my soil has barely enough of. I find turnips and swedes, and to a smaller extent most brassicas, respond remarkably well to a small amount of finely powdered bone adding to their soil on planting.
I reckon that although most brassicas can be started in either a seedbed or individual cells or pots the caulis and some broccoli's really resent it and are happier in a seed bed. But all do best if twice moved from the seedbed. Once to break the taproot whilst small and before many leaves have grown, and then again to the final position. The extra move makes for a bushier more fibrous root system that establishes better on the second move. I use multi-celled trays for the majority of brassicas though for the convenience especially as I have so many varieties to trial. They are planted out when tiny but given the protection of a plastic bottle tube each. These are open at the top which allows plenty of air but keeps off strong wind and many pests.
I also often propagate from suckers or basal shoots from the stumps of spent plants. These are easily detached when a few inches tall and rooted under a small cloche in situ where they are required. This combines well with my method of harvesting. Once cabbages are ready they are cut but the stem is left in the ground with a cross cut in the top. This then usually produces a second crop of smaller looser heads good for cooking or juicing as greens. When these are taken the stem is again headed back in hope of a further flush. This may occur and as often a flush of sideshoots and suckers also form if the plant does not die entirely. These are good for my chickens if not for detaching and replanting. I reckon some hardy cabbage plants have given me nearly two years of cropping before they expired or were pulled to clear the ground.
I don't recommend such perennial cabbages though unless you've got the space to play with as the yields and quality are higher with new plants than with the flushes from old ones. Likewise the perennial broccoli's are also poor returns for the space they occupy. One plant of a modern broccoli, Claret, cropped for me three years running and the final spring was almost a small tree with a trunk but the young plants gave more crop per sq. yd.. And of course such odd practice may be a problem where clubroot is in the soil. Fortunately I've not got it.
One interesting idea I have heard is why not graft the tops of susceptible to clubroot brassicas onto a set of resistant rootstocks. The small plants are pretty tough and wiry so it seems like this has a chance. After all tomatoes are grafted onto KNVF rootstocks for the same sort of reason. I have not tried but it should not be difficult if such stocks could be made available. It's said the usual strain of clubroot rarely attacks turnips or Swedes but I can't imagine grafting a cabbage on either of those, or on a kohl rabi for that.
The last mentioned is a superb brassica for difficult conditions. Little known it can be cooked or eaten raw just as cabbage but suffers far less from almost all of the common pests and diseases -including not getting the usual slug damage or intrusion! Kohl rabi also grows well in drier and poorer conditions, and it stores well for a long time. However most varieties are small and get tough when they reach any size, one though, Superschmelz, reaches football size and yet remains succulent all winter from store. This is a must for winter kohl slaws!
Of all the cabbages I've yet tried I must say Grand Prize does deserve the grand prize as it is extremely tasty and can reach a good size, it is distinctly better than others raw. Cauliflowers improve year by year as do broccolis, and Brussels' sprouts get smaller and sweeter than those big old jobs of yesteryear -mind you I love Noisette and that's no youngster. But the brassica beyond compare is Romanesco. This has the most amazing appearance especially under a hand lens and the flavour is exquisite with a succulence rivalling asparagus. Shame it's an absolute ****** to grow well.