Ollas are the place where our clay and garden intersect.
Ollas are an ancient irrigation system originating in Northern Africa with evidence of use in China for over 4000 years. They are still used in many countries today.
Ollas may be the most efficient method of plant irrigation in drylands known to humanity due to the mircoporous (unglazed) walls that do not allow water to flow freely from the pot, but guides water seepage from it in the direction where the suction develops. When buried neck deep into the ground, filled with water, and crops planted adjacent to it, the clay pot effects sub surface irrigation as water oozes out of it due to the suction force which attracts water molecules to the plant roots.
The suction forces are created by soil moisture tension and or plant roots themselves. Plant roots only pull water as needed never wasting a drop of water.
Ollas virtually eliminate runoff and evaporation common in modern irrigation systems, allowing the plants to absorb 100% of the water.