I read Rumors of Spring when it came out at the end of the '80s. I'd never heard of the author, and I assume I was taken with the title. In any case, I loved it, and bought his other books as they came out (until he lost his way a decade later). Rumors is still the one I like best, and so when my mind turned to Grant recently, it was this volume I picked to re-read first.
I recalled the book as being a somewhat opaque but lyrical consideration of the concept of plant mentation, and that's true. I'm not a fan of opacity for its own sake, but Grant pulls it off, in part because he has his characters constantly asking "But really, what's going on?" They never fully answer, but they're engaging in their effort. In particular, a curious teenage girl and a differently curious boy are central to the story; in some ways, this is a sophisticated young adult novel.
Grant throws out a number of threads, but he doesn't tie them all off; in fact, he doesn't really try. There are references, both direct and oblique, to fairy tales, religion, mythology, and they largely work. But some of the central mysteries are left unresolved. That worked better for me the first time around; this time, I was much more aware of the seams, and of the somewhat unsatisfying tangle at the end.
If Rumors of Spring isn't as striking a quarter century on, it's still a very good book. I recommend it to anyone looking for intelligent, subtle speculative fiction that combines conscience and story.
PS It turns out Mr. Grant was for a while married to the equally talented writer Elizabeth Hand - also worth checking out.