Mosaiculture is the cultivation of plants growing out of sculptures. The structure of each sculpture is usually made of wire frame and have irrigation paths built in, so the plants are actually alive, and growing.
Right now, the Atlanta Botanical Gardens is holding an event, all the way until October that displays mosaiculture creations. So if you’re in the area, it might be worth a visit. The largest living plant sculpture there is the Earth Goddess (first one shown below) which is 25 feet tall and is a permanent piece at the garden.