…and food can be a source of seeds. When I travel I like to go to a local market and get food-seeds. Corn and beans are great candidates.
They might come from a different climate but many of them can grow well in your garden and provide variety to your harvest.
Last year I planted Mexican blue corn (it didn’t do so well) and I will try this year country corn from the Canary Islands.
Beans are easier, and also need a lot less space. I’ve been successful with several ones already. You can save seeds from the plants that did best every year and you eventually will get them acclimatized to your local conditions.