Butterflies, I think no one has answered because no one really knows the answer.

I wasn't at all familiar that a potting soil existing that included a pesticide in it. Upon doing an internet search for "imidacloprid" it does sound a bit scary.

Personally, I think it's irresponsible of Bayer to be putting a pesticide in potting soil. That's sort of like a doctor prescribing and keeping you on antibiotics because you might get strep throat 10 years down the line.

I've hope you've seen your hummingbirds since the initial posting.

By the way, if you go to the bottom of the forum page, and do a search for 'bayer' on the entire garden web site, there's lots of posting of people who haven't had very good experiences using bayer brand fertilizers.

Glen