I have a list of plants I call “The Indomitables” that I give to clients who are novice or timid gardeners. All of the plants on the list are native species that, to put it bluntly, you would have to work very hard to kill. They are not favorites of deer or rabbits, and they do well in most sites except dense shade, yet they do not spread too aggressively, as some strong plants can do (for example, be careful where you put boltonia, because it will soon be everywhere).
At the top of my list of Indomitables is columbine (Aquilegia canadensis). This plant is in bloom right now and is unbelievably gorgeous.
This plant is about 2 feet tall, blooms from May to July, is pest-free (except for some merely cosmetic damage by leafminers), and grows just about anywhere. In nature, I have seen it in the cleft of a rock on the side of a mountain. It is taprooted, so it is immune to drought. I think it might not do well on a very wet site.
The photo above shows a plant that began blooming in a sunny spot last week. Here’s some columbine in a shade garden that gets only an hour or two of direct sunlight. This photo was taken yesterday.
Each summer, I collect the seeds of my columbine plants and scatter them on the ground in bare spots. They germinate readily and will grow anywhere–at least, I’ve yet to find a place they don’t do well.