Yes Daisy. Plants can & do adapt to some conditions & some plants are more "forgiving", about the conditions than others, under which they're grown...
I had one plant, which grows a long "tap root" & I just couldn't quite figure out, what was going on with it, as it kept failing to flower for several years, each spring.
Well, I was slightly "poking around" in the nearby soil & suddenly realized the tap root had grown sideways, amazingly just a few inches under the soil, almost three feet, from the "crown" ! haha
It just simply refused to grow downward, into a small area of "hardpan" soil, upon which it had been sown & found it much "easier" to grow sideways, than it ever could try, to grow straight down.
You've probably been amending your soil, for some years, adequately enough, to keep that Iris , in rather fairly good health. If you avoid chemicals, earthworms have a beneficial effect, too.
