Here's a palette of plants to choose from and fine-tune for your area. I've lived in a cold rainy maritime climate and a hot dry Mediterranean one. I love growing lots of things, and think it is better for us to eat lots of things, but I do think a lot about survival crops and yield per unit of space or labor. (When my home had only boat or floatplane access, I went to the store once every couple of months.) These are my choices for most reliable food in both kinds of places. If you pick 2 or 3 that suit your climate and tastes from each category, you'd have a well-rounded and doable set of crops.
For starch and calories, I think growing any three of these would give you dependable staples year-round:
love cool weather and are thus a fall-back for weird summers like this last one, where we got frost in mid-June. They are among the most drought-tolerant vegetables and have low fertility requirements. They go deep and bring up nutrients from lower levels of the soil, as well as producing a large yield. Before potatoes were introduced in Europe, they were the major root crop, particularly valuable during times of warfare, when fields would be burnt or trampled. The roots stayed safely underground. Tolerates extreme cold and stores in the ground.
have many of the above virtues, but gophers seem to like them better. They are not frost-hardy and have to have frost-free storage. They require a lot of nitrogen; being a tuber--that is, a swollen stem--they are not thrifty like true roots. However, they are easy to grow and very very useful.
Flint or flour corn
is easy to grow, stores at room temperature, and does not require all the threshing that small grains like wheat do. However, they do require warm weather, combined with irrigation in my climate.
is a blessing for those in summer-dry climates, as it can grow and yield on natural rainfall alone.
takes a lot of space and nutrients to grow, but the vines can sprawl over space that is not irrigated, or is not even soil. And really, wherever there are people, there is nitrogen, whether it's grass clippings, kitchen scraps, or urine. These are so easy to grow, store so easily, and don't have to be dug. Where I live, 100-degree days are followed by 50-degree nights, so I can't grow sweet potatoes. This is what most of us can grow instead. Use the little immature ones as summer squash. The male blossoms and even the young leaves are a great vegetable in their own right, and a free bonus. I suggest the rare drought-resistant heirloom Lower Salmon River squash. https://www.quailseeds.com/store/p34/Lower_Salmon_River_Squash.html
are easy to grow, yield a lot, and store at room temperature with no fuss. I love growing them. Common or French beans phaseolus vulgaris is the standard bean and comes in bush and pole forms. Pole beans yield more but take more labor and a longer season.
Fava beans, peas, and lentils
are all winter crops in warm climates or summer crops in damp cool ones.
are a good choice for maritime climates, as they like humidity, (it helps pollination) yield well in cool summers, and have a perennial tuber that will survive and regrow in low-frost zones.
Leafy greens are commonly skimped in the US, and those I find most useful are comparatively rare:
I love lettuce, but wouldn't devote much space to it in a survival garden, choosing cooking greens and wild greens instead for greater nutrition and versatility.
grows faster than kale, and has fewer pests. It is perennial in my climate, and can be harvested every week for much of the year. https://www.quailseeds.com/store/p9/Perpetual_Spinach_%28Leafbeet%29_Chard.html
are easier, faster-growing, and more pest-resistant than cabbage or broccoli, and much better adapted to heat and rain than kale, with all of the heath benefits of the brassica tribe. One variety, Old-Timey Blue, is perennial in my garden as well. Old Timey Blue Collards
is a native salad green with a mild, lettuce-like flavor. It grows during winter and early spring, filling the hunger gap nicely. It grows on natural rainfall, loves shade, and requires no fertilizer or care other than mowing down taller things that might crowd it out. We mow once or twice after the miner's lettuce has set seed. That's all we do besides harvest. https://www.quailseeds.com/store/p2/Miner%27s_Lettuce_%28Claytonia%29.html
make wonderful greens (cima di rapa in Italian) as well as the roots we all know about. Left in the ground over winter, they make a huge crop of leaves followed by a month or two of delicious flowerstalks. If you make sure to pick them before the florets stretch out and open, they'll keep coming all through the hunger gap, like little broccolini. https://www.quailseeds.com/store/p503/Seven_Top_Turnip_Greens.html
For flavor and vitamins, fruits are the jazzy top notes of the diet:
. Since these are a given in most gardens, I'll suggest a specific variety. Most tomatoes are good either for fresh eating or sauce. And most dual-purpose vegetables aren't outstanding at anything. But Italian Heirloom is a great as a fresh slicing tomato and great for sauce. Heavy fruit, big yields, easier than other heirlooms.
for homegrown spice
yield more and in a more easily stored form than other fruit, and can provide enough calories and bulk to be a staple. In climates too warm for them, I suggest prune plums, bred over centuries for drying and storing well.
in warm-summer climates and currants
in cool-summer climates are luscious and high-yielding with little care, on land too steep or shady or damp or rocky or scrubby for garden crops. They dry well.
Herbs and spices:
is not only an incomparable spice and medicine, but a source of energy as well, being oily and dense.
is hardy almost everywhere, draws, beneficial insects, is a versatile spice, is perennial, and has myriad medicinal uses.
My suggestion about herbs is to identify those you use or love most for cooking and have a few of those close to the house or in pots. Have a basic first-aid kit
--a wound herb like yarrow, a sedative like valerian, an aspirin analog like meadowsweet, etc. Work them into your landscape somewhere, not necessarily in an "herb garden". Then list all chronic complaints, constitutional weaknesses, or health issues that you and your family have, and learn to grow a few medicinal herbs to address those specific issues. For example, I have a tendency to respiratory problems, so I grow elecampane and take it all winter.