Making an Olla

Use terra cotta pots to create a homemade Olla.

30 min, Ages 5+

Ollas (pronounced “oy-yahs”) are unglazed clay/terra-cotta pots with a bottle or tapered shape that are buried in the ground with the top/neck exposed above the soil surface and filled with water for sub-surface irrigation of plants. They can be buried in garden beds or in a larger container to slow release water to your plants.

You simply take an  unglazed terra cotta pot and seal the hole in the bottom by gluing a penny over it with an exterior grade-water proof glue or adhesive. Then glue a second terra cotta pot to the top of the first. Now you have an olla! Bury your olla near your plants and surround it with soil. Next, fill your olla with water by pouring water in the hole on the top. Now that water can release slowly through the terra cotta, seeping into the soil gradually, over time. This way, your plants will get a slow release of water over an extended period of time. Refill your olla whenever it gets low. If you have time, you can invite students to paint or decorate the top of their ollas. For an engineering challenge, invite students to construct ollas with different materials or different shapes and compare the release of water from different olla designs.

Desert Oasis Garden Resources on Olla Gardening