You don't need to buy from a nursery. Buy an organic sweet potato from the supermarket, submerge it halfway in a glass of water, in a few short weeks you break off the slips/sprouts and plant them. You'll have enough sweet potatoes to feed your family for months from just one sweet potato. Just make sure the one you buy is organic. You can grow them in large pots if your ground has too much clay. I've also grown them in straw bales and they've done well.
Agree - very often small crops of this and that are produced in my garden simply by planting some of my produce leftovers instead of eating, giving to chickens or composting. The scraps don't
always thrive, but they are essentially free.
Free is good! And whether it started from organic is not so important as how it is grown in my opinion. If you grow an apple tree organically from a seed in a non-organically grown apple, you produce will be organic is what I'm saying.
Onions leeks garlic chives potatoes yams turmeric ginger horseradish sunchokes...
...can be grown from the root bearing parts generously cut off before you eat them.
Hot and sweet peppers tomatoes fruits of all sorts beans and peas corn etcetera...
...save a few of the seeds and plant.
And crops normally harvested when immature can have designated few left unharvested in order they may be perpetuated naturally.
Less work is good too!
If you have perpetual free garden areas you have more time for other projects.
I currently have virtually maintenance free perpetual ginkgo biloba chives onion greens sunchokes asian pears mulberries and patches of raspberries purslane pepperweed horseradish rosemary peppermint chickweed pokeweed and more.