it makes sense on a survival point that you keep eating you other crops like beans and courgette and save the winter crops for leaner times
I'm sure you're right there, but I guess these days we don't really have the survival thing to worry about... maybe in the future. As it happens, I try to get my parsnips ready asap because I want them yesterday, just as I do with sweet corn, and this year I managed the parsnips by the end of August... lovely they were too without a frost, but probably a heresy for some
. But seasonality changes with culture... for instance, some folk that follow the old Hayes Diet often substitute all year round the "neutral" parsnip for the "carbohydrate" potato in a meal. Myself, I just want them as soon as I can get them. 6 months of parsnips is better than 4.
On the seasonality thing, my more serious growing exploits over the last few years have really had an interesting effect on eating habits. When all the food was shop bought, there were a lot of rice/pasta dishes and all year round... tomatoes, baby spinach, peppers etc.... basically the more Continental/non English diet. Not any more. Potatoes are back on the menu for 6 months of the year, and rice hardly gets a look in these days unless it's in a cold salad. I now eat almost every temperate fruit going as and when it becomes available as opposed to my favourite one or two all year round from the shop. The boring "signature" dishes we can all be guilty of have largely disappeared to be replaced by different ways of cooking seasonal crops. Root vegetables have made a huge comeback in the Autumn/Winter. Beans are still all year round as that has always been possible in this country.