The other day, I made a couple of inexpensive ollas for my garden beds.
Ollas are an ancient irrigation method dating back over 4000 years ago. They were traditionally used in China and Northern Africa where they are thought to have originated from. Typically, ollas come in a bottle-like shape and are made from unglazed clay. They are buried in the soil with the neck sticking out and filled with water. Due to their microporous walls, water oozes out into the soil providing the surrounding plants with water. The idea is that the roots grow around the olla where they have easy access to the water. It’s a very effective and water-conscious way of watering plants as no water gets wasted and it is distributed right where it’s needed. They are especially useful in hot and dry climates.
Ollas come in all sizes which means that they are suitable for both garden beds and pots. They are most effective for crops with fibrous root systems like squash, melons, watermelons, tomatoes, and chilies.
Self-watering ollas are widely available in gardening shops or online, but they’re also very easy to make at home from inexpensive materials.
Make your own!
- 2 unglazed terracotta pots of the same size
- Glue or weatherproof silicone sealer like food-safe grade silicone for water tanks and indoor plumbing
- Bottle cap or cork to close one hole of the terracotta pot
- Saucer or small rock to cover the opening of the olla
Unglazed terracotta pots are perfect for making ollas. They are cheap and it’s easy to repurpose existing pots that are no longer in use otherwise. As a general guide, the smaller the pots the less distance the water will spread and vice versa. In good soil, the water should spread at least the size of the pot.
- Seal the drainage hole of one of the pots.
- Second, glue the two pots together by adding your adhesive along the rim of one pot. Then press both pots together firmly and wait for the glue to fully dry. This can take up to 24 hours depending on the glue/silicone.
- Test your olla for leaks by filling it with water.
If there are no leaks, go ahead and bury it in the garden bed. Leave the first few centimetres and the hole exposed. Gently pack the soil around the olla and fill it with water. Cover the small hole with a saucer or small rock to prevent rubbish, mulch or mozzies from getting inside.
Done! It’s too easy!
Check the water levels regularly. Depending on the size of your olla, it needs a refill every few days to a week. I check the water level using a thin bamboo stick.
P.S. Gardening Australia has done a great article on ollas. Go and watch it!
Olla watering pots, Gardening Australia: https://www.abc.net.au/gardening/factsheets/olla-watering-pots/11988902
Ollas, unglazed clay pots for garden irrigation: https://www.permaculturenews.org/2010/09/16/ollas-unglazed-clay-pots-for-garden-irrigation/