Of the tens of thousands of plants available our remote ancestors found a few they could not only eat but some they could actually grow for themselves. Even so in pre-Columbus England our range of crops was very limited. The most important basics for survival were grown in fields. Instead of vegetables in the gardens there would be quantities of culinary herbs, and more ‘herbal’ herbs, along with a few fruits of course.
How many distinct vegetable crops are there in an average kitchen garden? Most will contain between one and two dozen, seldom more. Perhaps if you counted each and every different cucurbit, allium and brassica you could find a couple of dozen varieties in an adventurous plot. And indeed if you added all the usual salad leaves, edible seeds, petals and herbs you would amass maybe a hundred or thereabouts. But even so this total is remarkably small when you consider the huge number of plant species.
One of the most noticeable changes in the kitchen garden over the last decade or so is the advent of raised bed systems. Whereas in the past the vast majority of all vegetable plots were very similarly run; on the flat and managed by an annual dig and a path and row system now there are a host of approaches and methods; many not on the flat and often without any annual dig. I somtimes wonder whether we're following reason and logic -or maybe it's just a fashion?
Over the years I have tried to grow almost every edible plant and crop and sometimes been surprised by outstanding successes. To some it may seem unlikely that we could cultivate any tropical plants here in the cold climate of Britain but of course with glass or plastic protection and additional heat we can grow almost anything; I've even produced respectable crops of bananas and pineapples.
One of our tastiest and most rewarding crops can be sweet corn, easy in the southern counties but a tad harder further north. This is not maize but a very distinctly improved sub variety, and far superior in edibility to animal fodder or starch and oil producing maizes farmers grow, or the mealie types from developing countries. In fact Sweet corn is almost solely an Anglo-American result of relatively recent breeding.
You never taste the finest sweet corn unless you grow it yourself. Buying frozen or 'fresh' cobs, from the supermarket or even a farmer's roadside stall, will not guarantee you really fresh. Even if you grow sweet corn yourself it's likely you may still not have had it absolutely fresh. You see in only a matter of minutes sweet corn starts to deteriorate, in particular it becomes more starchy and less sweet. The drive home in your car is long enough to reduce the quality noticeably.
Of all the plant parts we eat the most generally nutritious are probably the seeds. All the requirements for new lives are packaged inside and most seeds are thus very rich in nutrients as well as carbohydrates and or fats. World-wide we survive on seed crops, and their derivatives. Many are grown on an immense scale such as wheat, barley, rice, maize etc. In general these are hardly practical on a garden scale, it's not that we can't grow them but that they are awkward to harvest and process, and we need far greater quantities than most kitchen gardens can supply.
One of the perversities of our human condition is the desire for foods when they’re out of season. When our strawberries, asparagus and tomatoes stop producing at home foreign ones continue on the supermarket shelves till our next crops arrive regardless of their air miles. Many bewail this apparent waste of resources, others the lack of seasonality. The former critics forget the need for developing countries to sell us something- and surely fresh fruit and veg. are better than bush meats and drugs.
The way we lay out our vegetable beds should not be random or haphazard as it can have a strong effect on the behaviour of various crops and make a great difference to our workload. For example simply by aligning rows north south so that the land on either side of a tall row receives equal sunlight we can get very different results to east west arrangements where plants on the north side of a tall row live in perpetual shade whilst those on the south roast (with luck and in the northern hemisphere).
We almost all attempt to practice some sort of rotation though I suspect in practice expediency often messes up our plans. Many different examples are given in textbooks but unfortunately they are little use as guidance and can rarely be fitted to any gardener's particular needs. Individual tastes vary and few of us want exactly the same combination and quantities as are proffered in most textbook rotations. This is the main problem; these worked examples require you to sow, grow and then use the same vegetables in the same proportions as the originator.