S is for Snapdragons

Snapdragons are a beautiful annual. I love to use them in pots. I also used to use them in the actual flowerbeds each year. But then someone I knew who used to work in a nursery told me that they were actually harmful to nearby rosebushes. I have become much more wary of using them in the yard, then.

Photo by "aki_fukaki" on SXC

I would love to know if anyone has any insight into whether or not this is true. Thanks :-)