Yes, bananas are fine, my birds like them, guess I just left them out of my list! Collards are greens that look like spinach, you can purcase them in your produce section at your grocery store. Last time I bought them they were in a plastic bag. Spinach is also good for your birds, it is very high in calcium also. Here are some other items you can offer: brocolli, cauliflower, melon (watermelon, cantalope, honeydew, ect), turnips, kale, dandelion (you can pick this in your yard, just make sure it has NOT been sprayed with pesticides), brussells sprouts, celery, cooked beans. Sprouted seed is also a great way to get good stuff into your birds. I have a little sprouter I purcased in the garden section at Wal-Mart, they sold little packages of seed to sprout also. Hope this helps! Connie