Hydroponic Lettuce Wall
Lettuce is a plant that has quite a small root system and is therefore particularly suited to being grown in water culture. Because of the small size of each plant, hydroponic cultivation of lettuce allows for a huge density of lettuce plants to be grown.
As you can see, lettuce can be packed very tightly. A particularly creative way to grow hydroponic lettuce is in PVC pipes or in gutters that are hung on walls in a zig-zag pattern. Nutrients are pumped up to the top pipe or gutter, from where it runs down the pipe to feed the plants, and when it reaches the end, is passed down to the next pipe, which is angled in the opposite direction. Since lettuce doesn’t grow very high, quite a lot of lettuce plants can be grown on a wall.