Olla gardening by Curtis W. Smith, NMSU Extension Horticulture Specialist

Irrigation of plants by means of ollas, unglazed pottery jars, is an ancient practice. It was brought to the American Southwest by Spanish settlers and adapted to local gardens by Native American gardeners as well as by the Spanish settlers.

Over time, modern systems were adopted, but these modern systems are not as efficient as irrigation by seepage from buried ollas. Modern systems, even surface drip irrigation systems loose more water to evaporation and more likely to clog than ollas. When ollas are used properly, plant roots will proliferate around the moist clay jar, intercepting water before it can move through the soil by capillary action. This water intercepted by plant roots will then be used in the plant transpiration stream. This results in almost 100% of applied irrigation water being absorbed by the plants.

Olla irrigation solves problems for gardeners who cannot irrigate frequently, and is a boon for plants that should not be irrigated frequently. Ollas allow gardeners who travel as well as gardeners whose irrigation frequency is limited by water conservation ordinance to irrigate infrequently while still maintaining the health and beauty of their garden plants.

Proper plant and olla selection is important. Woody plants may break the pottery jars as their woody roots grow in diameter. Herbaceous plants are less likely to damage ollas. Olla porosity, size, and shape must be matched to plant water needs, root size and root distribution. Deeply rooted plants benefit from deeper ollas, shallow rooted plants are more efficiently irrigated with shallow ollas. The diameter of the olla may also be chosen to match the diameter of the plant cluster. Shallow, broad, ollas will provide adequate irrigation for clumps of grasses and annuals,

Olla plantings should be planted in clusters to maximize water use efficiency. While the planting group may be of one plant type, mixtures of grasses, annuals, biennials, and perennials may also be planted around a single buried olla. Mixtures of plant types may be used to create a more natural landscape. The olla clusters may themselves be clustered to create more expansive or linear plantings.

The olla pottery may become a decorative element in the landscape along with large rocks and flagstones. Portions of olla left exposed above ground should be glazed or treated to prevent evaporation.

To modernize these ancient irrigation systems, the jars may be recharged by a drip irrigation system, timed and sized to replace water lost from the ollas. Recharge of ollas may be done daily, or as frequently as allowed by water conservation ordinances.


Outgoing - snow peas (bottom right corner). Incoming tomatoes (middle of photo)

The Olla, according to the Spanish English dictionary means “pot” and was used by Spanish speaking countries as a cooking pot. These clay pots were initially used by ancient Latin American cultures to cool water by evaporation. The techniques used to cool the water by evaporation have allowed for a great way to irrigate your garden and provide water directly to the roots of your plants. The pictures below show the use of the olla in a local garden.

ollabed-2.jpg Positioning the 1.5 gallon ollas in the raised (4′ x 8′) bed

ollabed-3.jpg Digging to submerge the ollas in the ground

ollabed-5.jpg The olla goes into the hole

ollabed-4.jpg Burying the ollas

ollabed-6.jpg Another hole for one of the ollas (notice the seed catalog in ‘Mr Seed addict’ pants pocket!)

ollabed-8.jpg Ollas are submerged. One tomato, two tomato …..

ollabed-9.jpgHmmm, Farmer D & J decide how many should we plant?

ollabed-10.jpgThis one goes here, move this one there (still carrying the seed catalog in pocket!)

ollabed-11.jpg Filling up the ollas

ollabed-12.jpg A completed raised olla bed

:: Resources ::

More about clay pot irrigation – archived journal entries
Links & articles
BUY Ollas for your garden online supplier


  1. Evelyn says

    Thank you for thanking the time to take these pictures. I am buying some when I get my next pay check. Thank you a lot.

  2. PhoenixJen says

    Great pics! Love the commentary about the “seed catalog in the pocket”.

    The other day I visited a government building where I had to have my small purse scanned. There were “suspicious objects” in the bag so they made me emply out the contents, which included the following:
    –one water spigot for a rain barrel I was constructing
    –one package french breakfast radish seeds
    –the ubiquitous seed catalog (this one from Native Seed Search in Tucson, AZ)
    –a small notebook containing various drawings of the yard for water harvesting purposes
    –a “sheet” of plastic washers for hose connections
    –a pair of socks
    The guy sorting through my stuff gave me a really odd look.

    Hey – what can I say?

  3. Kaitlin says

    Thanks for the pictures and for listing the bed size. What size are the ollas you used in this instance?


  4. Anais says


    We are using 1.5 gallon ollas.

  5. Anais says

    Phoenix Jen

    Very funny! Thanks for sharing ๐Ÿ˜‰

  6. Devin Quince says

    What a great resource! We are going to try this in our garden once the snow melts.

    Here is our 2nd 100 foot meal with some weather changes

  7. Ginny says

    Very nifty! Thanks for the photos. ๐Ÿ˜€

  8. d.a. says

    I’ve never seen this sort of irrigation system before! This would work really well for our plot (we’re also putting in 4’x8′ raised beds, six of them).

  9. Emily B says

    Thank you for the information about the ollas.
    They are a wonderful way of watering gardens, especially when we can only use tank water, no mains for us.
    I have a different style of clay pot, but they are working wonderfully! Mine have been in now for two weeks and are no where near needing a top up. And the ground is lovely and moist.
    Thank you for the wonderful information!

    • Kate B says

      @Emily B, I too am in Oz, in rural South Australia. Have only just discovered (a) this website and (b) anything about ollas. Am hoping to encourage a local potter to go into production. How have you found these worked in the longer term?

      All the best, Kate

      • Anais says

        @Kate B: We’ve been using ollas for 5 years now and have 1/2 our water bill while maintaining nearly our 3 ton harvest on 1/10th of an acre. If you do a search on our site for “ollas” you’ll find many a post with facts and reference links. Good luck

  10. Laurie says

    Hi PTF! Thank you so much for the photos of ollas being installed. NOW I “get it” I guess I need to see it step-by-step. I am wondering if you have trouble finding the tops of the ollas (to add more water) when the beds are mulched and the plants are lush? Do you mark them somehow? Your garden beds look as “jungle-y” as mine usually get, and I can imagine searching through the growth to find the watering holes. Is this a problem for you? I am also very encouraged by the commenter who has gone two weeks on one fill up. >Wow< Thanks!

    • Helena says

      I put cheap funnels in the holes of my ollas so that I don’t “lose” them. Sometimes I silicon a smaller pot to make a funnel.

  11. emilyB says

    I just thought I would add to my comment above that when I FIRST PUT my ‘ollas’ in I fill the olla and also water the soil around it. Plants seem to recover quicker if it (watering) is done a day or so in advance, before planting or sowing seeds, as it is wonderfully moist.
    I love making tee-pea frames over the olla and then sowing directly the pea seeds.

  12. Carol says

    Great pictures! Beautiful gardens!!
    I am wondering if one could use plastic milk jugs with holes in the bottom to do the same thing…??? I can not afford the ollas right now, although I love the way they look, and the concept. Right now my garden is in the planning stage, as we are in chilly Massachusetts, but we are doing lots of dreaming!

  13. Anais says

    Thanks for the comments all. Glad you found this pictorial helpful.


    Yep, you sure can.

    Check out this article about using MILK JUG IRRIGATION

    • amanda says

      Hello ive heard a main problem using milk jugs is it clogs easily…i wonder if u placed the jugs in a pillow case before burying them….any thoughts on this? Thanks!

  14. toni says

    I’ve done the plastic milk jugs before. They don’t work very well. Use a needle to make your holes. Experiment before you bury them. Not too many holes. Maybe 3 or 4 to start. I gave up on that idea since my hydrant is in the middle of my garden and I can water anytime I want with well water.

  15. Moria K. says

    I have been cruising through your website for the past month or so and I am very encouraged and inspired to do what I can. I live in northern WI so our growing season is short but I am making the best of it. We live in the city on a 60×140′ lot(.2 acres) We are just starting out in the journey to increase our self sufficiency. We are using about 25×25 area of our lawn for the garden. I hope to take the master gardening course this fall and in the mean time I am experimenting with raised beds(we just finished making 15 of them and are in the process of filling them with topsoil, compost and worms) and now that I learned of olla irragation I am going to do a few beds in that as well. All of this is so brand new and exciting I feel like a child anticipating Chanukkah. Thank you for the inspiration.

    BTY Thank you for standing up for what God has put on your heart(asking people not to purchase from sundown Friday to Sundown Saturday). Praying God’s favor for you and your garden. May you recieve greater than your goal!

  16. Tim Maple says

    Hello. In my search for information on ollas to use in my own urban garden I stumbled across your site. All I can say is marvelous!! I am in love with the whole idea of becoming self-sufficient and I find your site interesting, informative, and just plain cool!


  17. Mary Doyle says

    I’m using a couple of ollas this summer and they are very satisfactory. Our clay soil gets very dry in the heat of summer so that irrigation is not always effective. With the olla, you can control wasteful watering by concentrating the moisture right next to the fine roots of vegetables and herbs. The soil retains moisture which makes it easier to absorb additional water in the vicinity of the plants. I have an old piece of glass that I set on top to keep slugs out of the olla and reduce evaporation. A rock or anything heavy would work. Next year I will be getting more.
    Mary Doyle

  18. Missy says

    What about problems with misquittos? Is there and issue with them? How have these pots worked out in the summer months in Phoenix, Arizona? What down falls and resolutions are there to problems using the pots?

  19. katrien says

    Thank you for the tutorial!
    I was thinking of throwing some ollas myself (on the wheel, that is, as in, in pottery making). I have two questions:
    1) What kind of clay are the made of? Terra Cotta, your average pottery (stoneware) clay?
    2) Are they fired?
    I’ll ask my pottery teacher if she can help.

    • Vivian Gentry says

      Everything I’ve read says Terra Cota and they would have to be fired or they would dissolve when you get them wet, you just don’t glaze them.

  20. mmartz says

    what is the size of these ollas? and how deep are your beds?

  21. Cirrelda says

    Hi – thank you Anais for this great post. I look forward to getting to know this website.

    On the clay – it should be low fire – any low fire clay – and adding grog (already fired ground up clay) or powdered mica or buying a low-fire clay that already has stuff in it for structural integrity for these forms.

    Then coil – starting with a pancake shape in bottom of a shallow small dish.

    I just realized we could do our own demo with photos!

    And firing it to cone 04 – 1900+ degrees. A ceramics supply shop could fire them for you. Of course, supporting a local potter is best. Maybe your local potter could provide a workshop.

  22. Kathi says

    YOu comment that it’s important to match the right size olla with the correct plant, etc. How do you determine this? Is there a guide?

  23. Mark says

    I was wondering how the garden performed watering with ollas. Did the plants do as well with ollas or did other methods produce better results?

  24. patricia says

    We bought a couple dozen olla’s from you last year but only had two beds and few oak whiskey barrels at that time. This year we made a few more raised large beds and added a few more barrels (barrels perfect for the olla’s) installed drip lines to water all of the ollas at once by turning the handle on the hose. OH MY OH MY. We have a few whiskey barrels with just drip irrigation 360 sprayers and no olla’a and what a difference the olla makes, all of the whiskey barrels (holding tomato plants surrounded by herbs or strawberries and herbs combined are thriving, just thriving, taller than the no olla barrels. Plants love them, when removing them this past winter, they were hugged by roots of vegetables that had grown with them that past summer. They work and work well, we all have been utilizing the plant nanny a clay spike that holds a wine bottle. They have the same concept as the olla yet can not be filled with the drip lines. look very nice in the whiskey/wine barrels. very vinyard feel to our courtyard now.
    We love it.

    • Anais says

      @patricia: Wow. What a wonderful OLLA success story. We love them, but it’s even better when we hear from others that they work so well. Thank you so much for sharing.

  25. Carla says

    How often on average do you water using the ollas? Also, I’m planning to use the square foot gardening method. I noticed that you put 3 ollas in a 4 x 8 foot plot. Is that pretty typical? We live in northern AZ, so our climate is quite arid. Thanks for all the wonderful info!

  26. Brian Wade says

    Great stuff!

    I might experiment using 3 inch diameter
    clay pipe and fittings for irrigation. Any


  27. Meredith says

    That is sooo cool! I’ve never even heard of Ollas before. I’m going to start looking around for some, or maybe make some myself, I have plenty of spare earthenware laying around!

  28. Duane Colbus says

    Love your Ollas! I use them as well, and to answer the question about mosquito, I buy a small roll of replacement window screen from the harware store. Then I cut ovals and place them on top of the olla, hold the screen down around the neck, and tie it off with brown twine. It is easier to do before burying your olla of course! This is an easy way to deal with the potential mosquito problem and still have fantastic olla irrigation!

    Tucson Arizon

  29. Agnes Clar says

    how should the ollias be spaced in a riased bed where I am planting
    A mixture of herbs such as rosemary, tarragon, chived, mints, dill, oregano,
    Mayana, serpentina, etc?

    Thank you!

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