Ollas In My Garden, 1 Year Later

Last spring I got my hands on a couple of ollas, and was eager to see how they would perform as the sole water source for a garden bed of tomatoes, peppers and flowers (see my post from last April, here). The concept behind using ollas--vase shaped, unglazed terra cotta vessels with lids, is to bury them in a garden bed, fill them with water periodically, and plant around them. Water slowly wicks into the soil surrounding the unglazed ollas, where plant roots colonize.

So...were they a success? Did they save water? Were the plants happy? Yes! On all counts, I'd say they did as well as drip irrigation. Here are the things I learned:

  1. On average, the ollas needed filling every 6-7 days. They wicked water consistently over the season. I expected them to need more filling during hotter months and heat waves, but it wasn't so. 
  2. Each olla wicked water at a slightly different pace. One of mine always wicked one-third of its water very quickly after filling, then slowed to match the pace of the other.
  3. The soil surface stayed dry. Water wicked from the bulbous part of the olla, keeping the soil surface dry and weeds from germinating.
  4. The plants surrounding the ollas needed no additional water.
  5. Each olla held 2.5 gallons of water, so roughly 5 gallons per week supported 4 tomato plants, 4 peppers, and a couple of cosmos and echinacea. 

In the fall, I decided to dig up the ollas and place them elsewhere. But as I dug around them, I found the soil there full of big earthworms, and the soil structure was incredible. A happy, healthy ecosystem had formed, and I just couldn't disturb that, so I opted to leave them and plant perennials around them. As warm weather returns, I'll begin filling them again. Now I can't wait to see how those plants thrive.

Ultimately, if you're a reasonably attentive gardener, willing to spend a few minutes per week with a hose and interested in saving water, this could be an option for you. I've seen automated filling systems, but I'm not inclined to go that far. If you garden in a place with cold winters, you would need to pull out the ollas before a hard freeze. 

Note: I know I know, I should have pictures of happy healthy plants growing around buried ollas. I wasn't that organized.