My balcony already has lots of parsley, sive and spring onions. Especially sive and spring onions are really easy to grow. Parsley is easy but a little harder than the first two. I also have Kale. Kale is a true survivor that grows fast and provides lots of leaves to eat. Kale will also produce lots of seeds for future plants. I advise mixing animal horns into the soil and using organic fertilizer.

Soon we will buy 5 new plant pots to add Habanero Chocolate, Paprika Mavras F1, and more Kale and possibly tomatoes. Tomatoes are not ideal for balconies though.