Old-tech Irrigation with Ollas
The Southwest isn't wet in the best of times and during a drought, like Right Now, it is downright parched. How do you keep a garden growing when the rain doesn't fall? We have to irrigate, but how can we irrigate effectively with scarce water? Drip irrigation is one modern answer, but ancient people had a simpler version of the same idea. Ollas are a simple, low energy and low-tech way to deliver water to plant roots with almost no runoff or evaporation.
What is an olla? It's a simple, un-glazed earthenware jug that is buried next to the plants it waters. The olla is filled with water, capped to reduce evaporation and mosquitos, then the water slowly seeps into the surrounding soil. After fruitlessly searching the local nurseries I bought our ollas from the Growing Awareness Urban Farm which supports needy families in Albuquerque. I even found a cheap and simple way to cap the ollas - old golf balls fit the top of our ollas perfectly! Thirsty annuals like chiles and tomatoes are planted around the ollas to draw water through the soil.
Another advantage of ollas is that they can be filled with either tap water or captured rainwater when it is available. Home drip irrigation systems usually run off of tapwater only. Using an olla is dirt simple - pick an olla sized to the garden bed or planter, bury the olla up to its neck, plant your annuals around the olla, fill it with water and cap. Just refill the olla when it runs low and you can water your veggie garden frugally and effectively. Our hand-made ollas can be reused indefinitely if they are unearthed and stored over the freezing winter months.
More Info:
NOAA.gov - Climate Prediction Center
Wikipedia - Olla
Growing Awareness Urban Farm - Ollas
NMSU.edu - Spanish Colonial Olla Irrigation Makes a Comeback
