I don't know anything about that particular Coreopsis, but feverfew needs to be deadheaded religiously or you'll have it everywhere. Mine grows in unirrigated areas like the gravel driveway, but I also get fairly regular rain most years. I also think that feverfew works best as a biennial since the plant doesn't look very good after blooming IME. In general the Coreopsis (mostly thread-leafed and lanceolata varieties) I've grown have been much easier and more decorative.