No drainage, so bed of pebbles underneath to help the soil dry out. Succulents seem to thrive in this setup. Other small potted plants enjoy the planters with only the pebbles and water acting as a humidity tray.
If I had a balcony - this is what it would look like! Love the pretty flowers growing from ground up to the first balcony and then up to second balcony and then up on the roof. What a pretty scene this would be!