A boon to having a ridiculous amount of plants/herbs: self seeders.
Many years of letting the plants "just go" has made my garden basil/parsley/cilantro/oregano (a perennial.. I know, but it's flowered and seeded too!)/garlic (off shoot bulbs, yada)/Egyptian walking onion (YES!)/dill (sort of) and now recently feverfew, California poppy and bells of Ireland seem to be going on autopilot. I find my India mustard to be easily self seeding too, but I know I'm supposed to "rotate" my beds and etc to avoid pests and disease. I try to tear up the mustard from the bed each year and replant it in a different place, but those everlasting seeds always crop right back up in the bed or wherever I've dragged the plant off to.
Not that I mind (I eat all the errant little child plants), but it can be a little weird when I find self sown seedlings in the garden path or in the flower bed or by the trash can.
Ah, an entirely self seeded vegetable/herb garden is THE perfect garden for me...
Diane Meucci at Gardens Oy Vey has self seeded Siberian kale ALL over her nursery, not just for looks, but for eatin' too. Definitely a worthy goal to aspire to.
On top of the self seeders, I'm working towards the perennial vegetable garden and have the asparagus bed, mache/corn lettuce/lambsquarters, (hopefully sunchokes), strawberries and garlic down. I'll probably be getting rhubarb sometime soon-ish from my awesome mother in law. Artichokes are a possibility, but seems a bit limiting for the space they use and I understand that sunflower buds are just as nice.
I'm still working on getting the horseradish to take to the pot I've been babying it in, but it was an abysmal mess last year. Incredible for horseradish too.
I had an air potato plant that I was worried would be invasive but never got to eat it. Then I lost the little seed air potatoes in the great frost/amongst the vines.
This book: Perennial Vegetables: From Artichokes to Zuiki Taro, A Gardener's Guide to Over 100 Delicious and Easy to Grow Edibles caught my eye a while back and I am somewhat interested, but I think it's geared towards those who are lucky enough to live in very nice zones, ie 8/9+
If you live in the right climate, lots of vegetables can become perennial. I hear in Florida eggplants and tomatoes are known to live just about forever .
Either way, I can't move my garden to Florida (and I'm not a huge fan of beaches anyway). So it's best to make do, get tricky with Mother Nature and build cold frames. Lots of them.