"Garden design is far more than just choosing appropriate plants for the site and properly spacing them in well-prepared soil. It's about creating an energy or mood that makes the owner or visitor feel comfortable and connected to the surroundings."
So says Laura Crockett in the current issue of Fine Gardening, distinguishing plants that have "personality" -- the "demeanor portrayed through their weepy forms or jagged leaves" -- and illustrates with a truly weepy Hakenochloa and a truly jagged Agave.
I mostly agree. But we humans anthropomorphize plants (and everything else) so extensively, is it truly fair for garden designers like Ms Crockett or me to decide for our clients what plant embodies what personality? That weepy Hakone grass, for example, may be comforting to me but evoke a sadness in you.
More properly, I think it's unfair to evaluate plants on just one aspect (in this case, their form: weepy or jagged). I might find the flowing shape of the Hakenochloa relaxing, but you might find its yellow variegation and violet winter tones invigorating! And the Agave may be just plain scary to me, but oddly reassuring to someone with a more Gothic sensibility.
So I would conclude that a plant's "personality" is a fiction projected by those of us who have emotions (in the human sense). It's not an objective attribute, and should not be the basis for a design the way form, color and texture are. On the other hand, if you're designing your own garden (as Ms Crockett's readers probably are), why not fill it with plants who evoke emotion and meaning for you? Just don't take my word for what that meaning is.