Ollas and Water-Wise Gardening

Dripping Springs Ollas

For the past twelve years or so I have been testing many garden products. Most of them are simple improvements on old designs. But I must confess, I am a simple guy and I tend to stick to the basics. I would rather carry around a quality hori hori than a bucket of tools, each with a specific function. However there are times when a specialized tool or piece of equipment is needed. And so started the search for a solution I had to a watering problem which ended when I discovered the wonders of the olla.

There are a number of places on my property that are not easy to water. In one location I have maxed out my drip irrigation system and hand watering is the only way to keep additional plants alive. In another area, the garden space has a building on one side, concrete on two sides and a gravel driveway on the fourth side. In addition, the water source is quite a distance away. So dragging a hose around has been my only option.

My Introduction to Ollas

Then I met Luisa of Plug and Play Gardens who introduced me to the wonderful world of ollas. Ollas (pronounced “oy-yahs”) are unglazed clay vessels for subsurface watering. They can come in many shapes; however the ones at Plug and Play Gardens are a tapered bottle shape with a small neck and lid. From my research this seems to be the preferred design.

Ollas are the Most Efficient Watering System

In “The Global Gardener”, Bill Mollison comments that the olla might be, “the most efficient irrigation system in the world.”  Used for over 4,000 years, ollas do not just leak out water. Rather they hold water in until plant roots draw the water out, where water molecules being draw into a root drag the next molecule of water along with it due to soil moisture tension. Eventually this bonding draws the water out of the olla. It is because of this process that plants only draw water out of the olla when needed. Soil moisture is constantly available near field capacity giving your plants full security against water stress.

Because this process is happening below the soil there is less evaporation of water from the soil surface. And as an added benefit, since the surface of the soil is not watered, there is less weed seed germination. The ollas put the water at the root zone of your plants where it is needed without waste. Drip irrigation cannot even make that claim although is comes in a close second.

After a year of using my ollas I have found them to be essential for water-wise garden. They were the perfect solution to tough watering situations. And while they are not appropriate for germinating new seeds, they work well on seedlings that have an established root system. I have been so impressed by them that we are using them at Woodward Gardens in Tigard, where watering the school garden in the summer is difficult. The tomatoes love the ollas and so do the teachers!