SOLVED. Sci Fi / Fantasy - Set in two "eras" - Plants "fight" back [s]

[Russell]

SCI FI - FANTASY - I read a book, I want to say it was in the late 80's or early 90's. That doesn't mean the book was new at the time. I found the book unique because there were two main characters. Each was from a different "era" on earth. The main character from the current era was a female police officer. In the second or third chapter, I recall her or her boyfriend pulling out a week from a sidewalk crack, and when they come back at the end of the day, the week has grown back and is even bigger than it was that morning. The other era seems to be in the past. Also a heroine in that era and I recall a dark ominous forest or trees doing something...coming to life? The unique part of this book is that each chapter (roughly) goes back and forth between the two eras.

I want to read this again and I can't find it. Driving my crazy. Thanks!
Russ

[Ayshe]

The Family Tree? Reviewers mention weed in a crack by their garage getting bigger despite the weed killer and shifting POVs between Dora, a police officer and slave girl.

[Michele]

Russell, still looking?

[Lobstergirl, au gratin]

I agree with Ayshe, sounds like the book. Moving to Solved.