I've been growing all my greens in an Attic for 4 years running and so glad I do. I run all the Boks, Chard, Mustards, Lettuces and many other greens, but started with and do best using some compact varieties. Baby Milk and Tiny Hedou Bok Choi, Tom Thumb, Tennis Ball and Little Gem Lettuce, Big Leaf Tong Ho, Mache, Mibuna are my go to set, and using things like Red Leaf Amaranth, Red Malabar, Sweet Potato vines, Micro Tomatoes, and Parisienne Carrots make it a fun garden. Herbs I use that work best are Chervil, Chives, Agastache, Peppercress, Nasturtium, Wild Zataar, Chamomile, and Dwarf Greek, Thai Sweet and Mammolo Basils. I've been set up under 100w, 600w, and 1000w led panels and been able to produce at every stage, well worth the effort. Pic of my "market corner" after 4 years, about 18 sq under 3x1000w with a dozen and half varieties of greens and herbs each.