The question I most often ask when I'm buying a plant is: does it last forever? I've never been a fan of stuff that dies after one season, or disappears in winter then resurfaces the following year just when you've planted something else in the gap.
I once planted a whole heap of perennials in one plot and when they died back in winter, I did a quick redesign in a completely different look. So I was furious when bright flowers appeared in late spring and wrecked my monochromatic combination of lichen-covered rocks, silver astelias, blue grasses and grey lamium groundcover.
With the exception of a silk tree (and you can't not have a silk tree), all of our trees and shrubs are evergreen. Vegetables, though, are a different kettle of fish, if you'll excuse the mixed metaphor. Most of those I grow are temporary visitors, lasting the season if they're not taken out by fungus diseases, bronze beetles, white butterflies, slugs, snails and cats.
Happily, I read something the other day on how to prolong the usefulness of certain vegetables and herbs. I'm trying it, mainly because it sounds like fun. If you have kids, they'll probably enjoy this too, and it may even cultivate their interest in real gardening that you can put to good use when you need a hand.
Carrot greens