What is an OLLA?

An OLLA is a clay pot used for irrigation. It is buried in the ground or container neck deep and filled with water to supply water to surrounding plants. The roots will grow towards and around the pot. The process works by soil moisture tension: when the soil is dry, the water is pulled out, when the soil is moist, water stays in the OLLA. OLLA irrigation has been used for thousands of years.

How does an OLLA work?

The OLLAS are made of unglazed, porous clay. When an OLLA is filled with water, the water is pulled out through the wall of the pot, due to Soil Moisture Tension. Roots of the plants help create a suction by absorbing available water, drying out the soil and causing tension in the soil, against the water in the olla, (think dry paper towel and water on a counter). When the soil is dry, water is pulled out of the OLLA, when the soil is moist, the water is not pulled out of the OLLA. This creates a direct supply and demand system. The roots will eventual grow toward and around the OLLA, allowing even and consistent watering. Plants are never over or under watered. If the OLLA is only partially filled, and there is a lot of rain, water will go back into the OLLA by way of gravity, decreasing the splitting of succulent fruits such as tomatoes and melons.

Why do I need an OLLA?

  • Conserving water is a stellar reason to use an OLLA. But, there are many other reasons to use an OLLA:
  • If your water use is restricted.
  • If you want to save time by watering less often.
  • If you container garden.
  • If you have a small area which is difficult to irrigate or gets sun all day.
  • If you cannot water your plants on a regular basis (travel, work, summer home, life gets busy!, etc.)
  • If you don’t like to weed since water in an OLLA doesn’t water topside weed seeds.
  • If you want healthier plants and better vegetable production since water is delivered at the root level.
  • If you are gardening at a school or in a community garden with limited water access.
  • If you want a smaller carbon footprint.

How do I use my OLLA?

Ollas can be used for vegetable gardens, flower gardens, tree saplings, berry bushes, just about anything that needs water to grow. The OLLA spacing will depend on plant selection, soil type, and temperature. As a general rule, plant 18 – 24 inches from the center of the Largest OLLA, and 10-12 inches from the center of the Medium Happy Face OLLA. This space will equal a 36”-48″ diameter circle around the Larges OLLA, and a 20″-24″ diameter circle around the Medium Happy Face OLLA.

Optimum plant spacing and distance will also be influenced by the root system and size of the plant. For instance, tomatoes are a large plant with an aggressive root system, so placing them at the edge of the wetting area will allow ample room for growth. The smaller plants can be planted right up to the neck of the OLLA. Some helpful diagrams for the largest ollas are below. A little experimentation and common sense will serve you well when deciding. If you have any questions, contact us! We love questions!

Do I plant inside the OLLA?

No. The OLLA is buried neck deep and filled with water. Plant OUTSIDE and AROUND the OLLA  pot.

What are the sizes of your OLLAS?

The XLarge OLLA is 13” from the bottom to the lid and 12” in diameter. It holds 2.9 gallons/11 liters of water. Our Medium Happy Face OLLA is 9″ tall is about 5″ across. It holds 1 quart/liter of water.

How often should the OLLAS be refilled?

This is determined by a few variables: how much water your plants use, soil type, temperature, and rainfall. Also, the OLLAS are hand crafted so there may be some minor variation among pots. On a conservative side, fill the OLLAS 2 times weekly. If your area gets around 30 inches of rain annually, you may be able to go for 5-7 days without filling the OLLA. If mulch is used as a cover, and your area gets a little rain monthly, it is possible to go up to 10 days without refilling. You’ll find the pattern for your area with a little observation and common sense!

How deep do I bury my OLLAS?

Bury the OLLA with enough of the neck exposed so that soil and mulch do not wash into the pot. Leaving 2 inches showing above ground will usually do the trick.

What plants can I use with the OLLA?

You can use the OLLA with any plant: vegetables and flowers, of course, but also trees and shrubs. Putting an OLLA by a new tree or shrub will help get the plant through that first year. If you feel the root system is well developed after one year, dig the OLLA up and use it somewhere else. Your local nursery would know more about normal tree and shrub root growth. Keep in mind that woody roots from fast growing trees and shrubs are very strong and over 3 or more years could wrap around the OLLA and eventually crack it. Wisely use the OLLA to get these plants established, however long that takes, and then move the OLLA to use on another plant.

Click here for ideas!

Do I need to dig up my OLLAS every winter?

We say No, if you do a few preparations. Our ollas have very thick walls which help keep them stable. Our  XLarge 11 liter/2.9 gallon olla has withstood many consecutive winters in the ground in southern Canada, as well as in Maryland, Virginia, Utah, and Peninsula, to name a few states. But every area is different, so we say error on the side of personal experience and common sense.


FIRST, 14 days BEFORE your last frost, make sure the ollas are empty, no water should be in them. SECOND, Cover the lid. Some straw and an inverted bucket will do. THIRD, Pay attention to your particular location. If your area is prone to heavy rains quickly followed by freezing tempertures, we suggest you dig up your ollas for the winter and store them in a dry place. (Be on the watch for a Youtube on “How to Easily Dig up a Dripping Springs Olla”.)

Click the pictures and read the captions for more detail. Also, we are testing ollas all the time. 

Why does the OLLA need a lid?

The lid prevents evaporation and keeps out mosquitoes, frogs, slugs, dirt, leaves, etc.

Do I need to water my new plants/seeds?

Yes, when seeds or young plants are put into the ground, they will need topical water until the roots are established enough to draw from the OLLA. After that, the OLLA will do all the work.

How long will my OLLA last?

Your OLLA will last for years, with a little TLC. If leaves or light things fall into the olla, fill the olla with water and as the item floats up, swish it out. If you find a lot of dirt has accidentally gotten in the OLLA (it happens), dig the OLLA up, tilt in on its side and spray the inside with your hose until the dirt washes out. You can clean your OLLA with a 1:1 mixture of vinegar and water if your water is full of minerals. Pour one gallon of water AND one gallon of vinegar in your OLLA and let it sit for a few hours. Use a scrub brush for removing debris on the outside. First, remove the OLLA from the ground if using a vinegar cleaning.

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