What plant is easiest to grow for food?

If you are looking to feed yourself no single plant is going to provide what you need. Potatoes do provide a lot of things the body needs but not all of them. Unfortunately potatoes are highly prone to blight which can destroy an entire crop. Even blight resistant varieties aren't immune. Closely related are tomatoes though they can usually survive if you do some trimming of the effected areas. Blight is in the soil which splashes up on the leaves when it rains infecting the plant. A heavy mulching of straw can help but won't always prevent it. Both potatoes and tomatoes can do well in large pots or buckets if space is a problem. Both require a considerable amount of time to mature. It is possible to get a second crop of potatoes depending on the varieties you plant and the length of your growing season. Here in Missouri I can get two crops.

Radishes are probably some of the fastest plants to produce. Although not a lot of people like eating them. Some of the Daikon varieties are milder in taste. Their main drawback is that they have very few calories and you have to eat a ton of them.

Most common greens grow fairly quickly and can be eaten at almost any stage of their development. This includes onions but most people leave them in the ground to grow large bulbs and that can take awhile.

Nearly everything will produce seeds, even potatoes. Though many varieties of potatoes rarely produce seed pods it's still possible. Growing potatoes directly from real seeds is much more time consuming and in most areas of the US they must be started indoors many weeks before planting them out.

It is knowing WHEN to harvest seeds that's important. If the seeds haven't matured yet when harvested they may be useless. The cucumbers you buy in the grocery store do not have mature seeds in them. Cucumbers need to over ripen on the vines and will often turn yellow when they are really mature.

Some seeds can be purchased in bulk from your local grocery store. All beans are really seeds and will grow. Hard dry whole peas are also seeds. Split peas can be questionable. Usually only half will actually sprout. No seeds that have been canned will grow. They are cooked in the canning process and are dead.

Gardening isn't rocket science and even the newbie who has no idea what they are doing will usually get something to grow. You can greatly increase your chances of a good crop with just a little searching on the web. YouTube is a great source for new gardeners. Even I who have been gardening for fifty years still manage to learn something new now and then by watching others.

Easiest to grow will depend on your climate. In North America the potato is probably the easiest and give some nutrition with enough carbs to survive. Other grain crops will also help for survival but they take most of a season to mature.

try herbs and leafy greens to start. they're insanely beneficial for humans. and you can eat the leaves! unlike a fruit or veg that needs to grow individually and mature and rippen. and while this all happens you can compare the freshness and vitality of the leafy greens to those that are store bought. leaves grow quicker than a whole entire pepper or watermelon for sure. :)

Sorghum is a fairly easy to grow grain that has a high sugar content. It can be used to make molasses, ground into flour, or used as animal feed.

Zucchini/summer squash, tomatoes, lettuce, beans, and most herbs are all pretty easy, but the easiest is probably radishes.

chard

zucchini

summer squash

New Zealand spinach

radishes

beets

turnips

lima beans

pumpkins

winter squash

Georgia collard

tomatoes--huge yield for a small area-so easy to grow!

I would say green beans. They produce well and are easy to store. You can can or freeze them.