Olla, 1.9 L, Terra Cotta - Small Burry the olla between the plants in a border or planter. After filling the terracotta pot with water the roots of the plants will draw water from the pot. This form of irrigation can save up to 70% of the garden's water consumption. – easy to use – saves up to 70% of garden water consumption – saves time – too much or too little watering is not possible – fewer weeds – fewer snails – ensures a better soil structure.