If you look at illustrations of 19th century middle-class gardens, you see a lot of things you don't see so much anymore: things like Hollyhocks (used to be a lot more common, anyway), Four-o-clocks, any one of several different kinds of annual Poppies, Nicotiana, Calendulas, Snapdragons, Campanula media, and so on.

They had Petunias back then, and in those days they were still dependably fragrant. The flowers were smaller and came in a smaller variety of colors (often with a contrasting "starburst") but they held up to the weather better and were significantly more vigorous. Another difference was that in those days, at least in the warmer parts of the USA, Petunias were fairly easy to grow from seed planted in-situ. One did not buy hothouse-grown seedlings.

In the cooler parts of the world on the other hand, "Nastutiums" (Tropaeolums, actually), were very common. You see them all over "Peter Rabbit" illustrations from Edwardian England.

What I am talking about, of course, are "hardy annuals" and in part hardy biennials. You don't see them much anymore. They have mostly been replaced by hothouse annuals like the modern overbred Petunias, Pelargoniums ("Geraniums"), Impatiens xsultana (or whatever it's called these days), overbred modern "Marigolds" (actually "Tagetes"--real Marigolds are hardy), and similar tender annuals, tropical perennials, overbred plants whose seedlings can no longer survive outdoors, and other plants that are now mass-produced in hothouses.

Because of the cost of hothouse annuals, the fact that they don't perform all that well in my cool maritime climate, and the fact that constantly replacing them multiplies opportunities for introducing new diseases into my garden, I don't buy them anymore.

In my cool summers, Clarkias (which some people know as "Godetias") perform the same function but reseed themselves dependably, don't mind poor soil, bloom much, much longer, and are a lot less work for me. I carefully guard my beds, because they are hard to replace if I ever lost them...they have been replaced by ugly overbred dwarf hybrids.

There are a lot of very pretty and interesting annuals from California--many of them endangered in habitat. Chile also has quite a few from similar latitudes and climates. For rougher climates there are hardy annuals from Central Asia and similar coldwinter grasslands.

Look for suppliers of "heirloom seed". Unfortunately, a lot of it is not really "heirloom"!! However, you can sometimes find wild or near-wild versions of a lot of things that reseed themselves better than their too-domesticated kin. Sometimes it helps if you help them reseed for a few generations, until they start reverting.