Friday, April 10, 2015
The Garden Olla Project, Part 1
This is due to a unique feature of these low-fired clays. They are slightly porous. (This is, after all, the same clay used for flower pots. This is why clay flowerpots "breathe".) Pour water into an earthenware pot and it will quickly soak into the fabric of the clay, turning it to a darker red. Wait a while longer, perhaps half a day, and you will find a little pool of water beneath the pot. Often this not desirable, which is one reason why glazes are applied on earthenware. Glaze, with its fully melted glass-surface, renders the pot non-porous.
However, time out of mind, there have been uses for which the porosity was indispensable. A water-filled jug is kept cool by surface evaporation. Objects immersed inside remain cool, even in high temperatures, and especially in a dry climate. Drinking water is kept cool. And in the garden, the seepage itself can be used to slowly release water to the roots of thirsty plants. There is minimal water loss as the pot is buried in the soil itself, allowing all the water to flow into the plants' root zones.
Many traditional ollas (as these pots are known in Italian and Spanish) are large, containing 2 gallons or more of water. Mine... well, they are not very big. Just some small jars to test the idea and hopefully extend the necessary time between waterings as summer warms up.
I am finished with part one of the task: making the pots. Handthrown on the potter's wheel, then dried...