If you want to be self-sufficient, or have to be because of where and when you rare:
1. You grow multiple things so you have options.
So you might grow wheat to pay taxes, barley for brewing, potatoes as another source of carbs, peas or beans to refresh the soil, some other root crop as fodder for animals in the winter; have some fruit trees, have a kitchen garden for vegetables and herbs
This diversity doesn’t wear out the soil as badly as monocropping does and it means you have work to do all around the year
2) You are more reliant on storage and preservation for times like the winter. This is why you have granaries, barns and root cellars. Canning and jam making if you are more modern. A lot of traditional dishes (pickles, sauerkraut, confit, ham) are for this purpose.
You might not be able to keep all your animals alive over winter, so you slaughter and preserve the excess in the autumn
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