In a world of high-tech sprinklers and automated gardening apps, it is great to see a centuries-old system make its way back into backyard gardens—the olla irrigation system. This ancient garden watering technique, rooted in history, offers a fascinating alternative.
If you have ever seen what looks like small ceramic pots buried neck-deep in a garden bed, possibly even with a lid on it, then you have seen an olla (pronounced oy-yah). These simple, unglazed clay pots have a long history. Used for thousands of years by ancient cultures across Africa, the Middle East, and the Americas with a surprisingly modern purpose—efficient, smart gardening watering.
An olla is a round, porous clay foil buried in the soil, with just its neck above ground. Gardeners used to fill it with water, and through a natural process called osmosis, water will trickle slowly through the walls of the pot. The soil will essentially pull the water, and the plant will drink it straight out of the soil up by the roots. It’s an ancient garden watering technique still relevant today.
It is remarkably efficient since it diminishes evaporation and run-off; plants are never too wet or too dry. And since the water is underground, it’s great for hot or dry climates where surface watering evaporates before reaching the root zone.