Recreate an ancient irrigation method that keeps plants happy, even in arid environments. Pronounced oh-yah, olla clay pots were used as low maintenance drip irrigation in China and North Africa thousands of years ago. Though still used around the globe, they can be expensive in the United States, and their popularity with busy or drought-stricken gardeners has made them harder to find.
This Gardening Australia video demonstrates how to “irrigate like it’s 2000 BC” with DIY olla pots made with two inexpensive, unglazed terracotta pots, food-grade silicone sealant, and a cap or stick to help plug the holes.
Traditionally shaped like a gourd, the handmade watering vessels are buried to their necks in the soil. Filled with water, they irrigate the surrounding plants with slow and consistent moisture. NativeSeeds.org explains:
“The porous walls of the olla allow for water to dissipate into the soil as needed. Because the pores in the clay pot are small, the water does not freely flow out of the pot. A suction force is created by soil-moisture tension as well as the plant roots.
“If soil is dry, the water inside the olla will release faster as the soil roots ‘pull’ it out. Likewise, if there is a recent saturating rainfall the water in the olla will remain until the surrounding soil dries. Therefore, olla irrigation is extremely water efficient and prevents excessive evaporation and water runoff.”
With an estimated water savings of 50% to 70%, this method keeps plants well-watered and keeps roots cool, too. Just keep them at least 50% full and be sure to cover them to keep dirt and mosquitos out.
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