I just got a fine from the Neighborhood association - $10 for two weeds. I checked my yard and there is not a single weed in it.

jsweeney, maybe you need to brighten your weeds so you can see them better. Sometimes they blend with the other foilage.

The weeds often merge in with the rest of the foliage in the garden so they're difficult to spot. I do dislike getting that event. Especially as it usually happens when the game is started up and you've not had a chance to look round to pull any weeds that have grown while the game was off.