I had heard it at my vets, and when I googled it it appeared on several food lists so I have been wary of a few things since.

http://www.starbreezes.com/11/foodsafe.html

http://www.wisegeek.com/which-foods-...s-and-dogs.htm

http://www.submityourarticle.com/art...dogs-26128.php

As I had an unexplained sudden death (I paid for an extensive post mortum) on an otherwise apparrantly health young Chihuahua which devastated me - I have always felt that I would prefer to err on the side of caution. With my dogs also being very small I suspect dosage levels of certain things would be higher to them than say a GSD a labrador or a newfoundland sized dog.

I've replanted my struggling 2 plants the right way up now and put them higher up on a garden utensils container.