I forgot about white marigolds until I read your post. One year I grew "Vanilla." It was a great flower. I didn't use it as a cut at the time, but, I'm sure it could be used as one.

I tried Vanilla in 2010. Unfortunately it does not behave like the Gold Coin series. Pinched and ended up with alot of short branches. Terminal flower stem was only about 18" tall. It sure was nice is short arrangements though. Shade, since when did Marigolds need shade ????? Full sun, all day.
Cheers Kim
Billabong Fresh Flower Farm