Growing greens in flats. Making vanilla.

The post has nothing to do with my batch of vanilla, but isn't it pretty?

I keep seeing greens planted in flats in book, blogs...everywhere. I have decided to give it a try. They are often grown in the house under lights. I have plant eating cats, so it would never survive. I have decided to try it in the greenhouse. I won't use the lights unless I think I need them.