I believe every garden has a cornerstone plant. In mine, it's the banana trees.
Banana is a tropical fruit, but some varieties can be grown as far as Canada (it doesn't usually fruit as far north though).
Granted, if you are in temperate climate like me, it's not the same fruit as the Ecuadorian ones. Each area will have a different variety adapted and mine are shorter, fatter and have a distinctive and stronger taste than the bought bananas.
Why do I say it's the corner-stone? Because it concentrates organic material, nutrients and water in a way that I later on use to increase the vitality of the rest of my garden.
Banana trees are not trees, they are grass. They are a grass that can grow to five meters tall in six months. How cool is that?
I use the fruit both green and ripen for different preparations.
The favorite with ripen fruit is banana ice cream. Because it ripens all at once, I freeze the bananas, so to make ice cream I just take out some, add a tiny bit of milk, some sugar or honey, process it and it's ready to eat...
With green bananas I make patacones. It's a double fried system that makes something like a cracker. It's not typical of my area, and I don't love fried foods. So I make it only from time to time.
The male flower and heart of the stem are also edible, though it takes some more work (fibers removed, double boiling, etc).
I have done pancakes with the red skin of the male flower, something like false palmettos with the center of the stem and cooked the center of the male fruit several times in a sort of sautee with onions etc.
The leaves are used to make food "packages" of different sorts. I use them to replace the aluminum foil in pans.
The stems can also be used to make rope and fabric, and the list goes on.
All in all, it's a great plant to have in any garden. It does require a lot of water, so the best place to put it in on the sides of streams or, like in my case, I dedicate part of the water of my roof just to feed it.
Some science:
Bioactive compounds in banana and their associated health benefits - A review
pubmed.ncbi.nlm.nih.gov/27041291
"Banana contains several bioactive compounds, such as phenolics, carotenoids, biogenic amines and phytosterols, which are highly desirable in the diet as they exert many positive effects on human health and well-being. Many of these compounds have antioxidant activities and are effective in protecting the body against various oxidative stresses. In the past, bananas were effectively used in the treatment of various diseases, including reducing the risk of many chronic degenerative disorders."
Imgs: Some plants in my garden.