Ha ha Kosk -- that has been my exact experience with cilantro. Yet my non-gardening friend had it growing all around her house foundation up in Sedro Woolley. They mowed it regularly but it just kept coming back. She just thought it was some sort of weed.
And I think basil may also need extra watering. I really don't do any regular watering, although the past couple summers have rather forced me to revisit that. We have a couple outdoor faucets that leak and need some replumbing and my husband is actually talking about running an irrigation line out to the herb garden. I'm afraid once we start that, there will be no going back and we'll soon have a fully irrigated yard. (Not a bad thing.)