Like you I don't like marigolds but I found an old bed beneath massive & dense weeds in the front of our French cottage bordering a road. The bed has very poor soil & is very dry, I chucked marigold seeds around with gay abandon & unfortunately I forgot them for weeks whilst making new borders around the rest of the cottage but when I did check on them they were magnificent & flowered abundently with very little care right through until the first frost in November. Bad soil, very hot, 2,500ft above sea level & they still performed - marvellous!