How to Make an Olla or Why Having to Use Southwestern Drought Techniques in the Southeast Is All Kinds of Wrong

We are into week two of the crazy late spring heat wave that struck us last week.  It’s been over 90 (and often as high as 96) every day this past week and there’s no sign of it cooling down anytime soon.  Our grass is getting crispy and the only reason we have to mow is because all the weeds are going to seed after having a raucous weed orgy in a desperate attempt to procreate before they die.

Note the hot weed fornication going on in the background.

This type of dryness and heat makes me very anxious for our area farmers.  This kind of heat isn’t out of the ordinary for late July and August but it’s usually combined with high humidity and afternoon thunderstorms are very common.  This weather reminds me very much of the summers we had drought conditions and I’m doing everything I can to get my garden ready just in case we are dealing with that again.

A few years ago, we experienced a couple of very hot, dry summers so we put in a drip irrigation system in our garden beds.  We also mulch heavily and try to make sure our soil has as much organic matter in it as possible by using lots of compost.  Even doing all this, we noticed a reduced yield from our garden and we were concerned with how much water we were using.  I started doing some research into water saving techniques used in drought prone areas.  That’s when I discovered ollas.

Ollas were routinely used in the Southwest as a way to irrigate plants and conserve water.  An olla is an unglazed ceramic jar, typically with a very narrow neck.  These containers are buried in the garden so that the neck sticks up out of the ground.  They are filled with water and the water slowly seeps from the jar into the soil, thus watering the plants.  Ollas pretty much eliminate any run-off or evaporation of water, allowing almost all of the water to go to your plants roots.

Ollas are gorgeous looking jars and they seemed to be the answers to my prayers.  Unfortunately, they also seemed to be rather expensive, especially when I had to factor in the cost of shipping them.  Then I began to wonder if I could make one.  However, the last time I worked with ceramics was when I created a pot for my Mom for mother’s day when I was 12. It had to be one of the ugliest monstrosities I’ve ever seen and just the fact that my mom was willing to display it in our house proves her unconditional love for me.  For the love of God, it was poorly made and a horrible Pepto-Bismol Pink.  I was secretly grateful when my Cat from Hell (AKA Snow White) sacrificed it up to the pottery gods.  Needless to say, while I’m willing to give pottery another try someday, I didn’t hold a lot of hope out for creating an olla of my own in a ceramic studio.  I still wanted to try ollas though.

Back when I learned about ollas, there wasn’t a lot of information out there on how to make them yourself.  I did find some information on how to make your own ollas from the Santa Fe Master Gardeners Association and Austin’s Water-wise enews. So I set out to make my own using two terra cotta pots, silicone sealant and a milk cap.  They were easy as pie to make so I made four of them and placed them in my raised beds.

I actually used two pepper beds as my test and control beds and by the end of the summer, I was convinced that the ollas had made a noticeable difference.  Both beds have received equal amounts of sun and water (they’re both connected to my drip irrigation system) and the soil was similar.  Both beds were planted with a mixture of sweet and hot peppers with a few flowers planted as well.  The pepper plants in the bed with an olla in it were noticeably fuller and greener and out produced the other beds in terms of pepper production.

My garden beds are 3 feet by 4 feet and I think one olla per bed this size works well.  I can’t dig them in as deeply as they can in the Southwest (thank you East Tennessee red clay) and the necks aren’t nice and narrow so they do take up more space but I think the trade-off is worth it.  What I usually do is plant my vegetables around the perimeter of the beds and then plant flowers and herbs around the olla.  I also keep the open hole at the top covered with a small rock to keep small critters from crawling into the olla.  If you’re so inclined, I’m sure you could craft a cover for these from a clay saucer and decorate it.  I wanted to bedazzle a cover but a squirrel ran by and distracted me so I put that idea on hold for a while.

Over the years we’ve placed them in other beds and we added a few more this weekend so I took some pictures so that I could show you all how to make them.  I tried to include all the instructions you would need to make them, even for those of you who get frightened when you walk into a Lowes.  If you have any questions, just ask me in the comments.

Equipment Needed:

  • Two 8-10 inch terra cotta flower pots (I use both 8 and 10 inch ollas)
  • Silicone caulk (make sure it’s marked as being appropriate for exterior use) & caulk gun
  • Something to plug the bottom hole: milk cap, broken bits of tile, stiff plastic cut out of old plastic pot or milk bottle – it just needs to cover the opening of the bottom by at least a half inch on all sides.
  • Utility Knife
  • Cardboard to set the pot on while you’re working on it because if you’re like me, you’re going to make a mess

When you buy the flower pots, make sure you check to see that the top lips of each pot match up reasonably well so that you can make the tightest seal possible.

Load the tube of caulk into the caulk gun.  Cut the very end of the tube of caulk off at an angle.  Down inside the plastic tube, there is a seal that needs to be punctured with something long and thin, like a screwdriver.  Now you’re ready to caulk the hell out of something!

Using a gentle, steady pressure, squeeze the caulk gun so that caulk comes out evenly and caulk around the outside perimeter of the lid.  If you’re using tile of a bigger piece of plastic, make sure to apply a decent amount of caulk around the edges.

Place the lid in the bottom of the pot so that the hole is sealed.  Press firmly, but not so firmly that the caulk all squirts out.

Next, apply caulk all around the top edges of the pot.

Place the other pot on top of the caulked pot so that both of the tops meet.  Make sure that the tops match up on all sides.  Press down lightly, but not so firmly that all caulk squishes out.

Look and see if there are any gaps that need to be filled in.  If so, fill in from the side with the caulk gun.  You can also use your fingers to smoosh caulk into any areas that need filling.  You don’t have to worry about this looking pretty because it’s going to be underground.  Let this dry for at least 24 hours and then fill with water to check for leaks.  If you find a leak, gently tip over to let water run out, let dry in sun and reapply caulk in the area leaking.  Test again for leaks.

Dig a hole in your garden where you want to place the olla.  You can place the olla as deep as you’d like.  Many people dig their ollas down so that the olla is almost level with the ground.  I would do that but I don’t like to drive myself insane by chipping millimeter by millimeter away of solid, red clay over several hours using a only a shovel in the sweltering heat.  I dig down until I want to kill someone and then I place my olla.  Most of mine stick up a few inches from the garden bed.  One sticks up more than that due to tree roots.

Place the olla in the hole and fill in dirt around it.  Pack the dirt in reasonably tight.  Fill with water and cover the hole on top with a rock or your custom bedazzled cover. Your garden bed is now ready to plant.

The easiest way I’ve found to check the water level is to use a long stick.  Put the stick through the hole in the top and push down until it hits the bottom.  The area that’s wet shows you where the water level is.  I’ve found that my ollas need to be refilled anywhere from 2 to 7 days.  It really depends on how much rain we get or how much we have the irrigation system on.

I’d recommend taking them inside in the winter, especially if you live somewhere with more severe winter weather.  To be honest, I’m lazy so we’ve left ours in the garden over the last few years years and none of them have sprung any serious leaks.  I also mulch over them fairly heavily come late fall.

I’m an olla convert.  They really have made a difference in my garden.  It does disturb me that I’m employing Southwestern drought techniques in a garden that is less than 40 miles from a temperate rain forest but besides using use less carbon fuels and conserving water, there’s not a lot I can do about that.  I’m counting on ollas to keep my garden going this summer if worse comes to worse.  But I’m still worried about the farmers.


12 Comments on How to Make an Olla or Why Having to Use Southwestern Drought Techniques in the Southeast Is All Kinds of Wrong

  1. Gina
    June 6, 2011 at 9:50 pm (3 years ago)

    Do you have any suggestions for planting a garden without actually going outside? It’s hot out there!

    • Kristina
      June 16, 2011 at 4:08 pm (3 years ago)

      You would think that eventually I would learn from my procrastination. Alas, it never happens and I cooked myself last week.

  2. Lisa
    June 7, 2011 at 3:12 pm (3 years ago)

    I’m totally trying this. Thank you!

    • Kristina
      June 16, 2011 at 4:09 pm (3 years ago)

      You’re welcome! Let me know if they work for you!

  3. The Modern Gal
    June 8, 2011 at 9:58 pm (3 years ago)

    Oh wow, I really, really need to try this. The plants in our front beds are so far gone from lack of rain, lack of nutrients, excess of heat and excess of weeds. I finally just gave up until I could do something about it in July after we’re back from the honeymoon.

  4. Cynthia
    January 29, 2012 at 12:53 pm (3 years ago)

    I am sooooo ready for season. We would love to get together and talk about “tomato porn”!!!!!! Call me and let’s have you over to our house!

  5. michael
    April 26, 2012 at 4:34 pm (3 years ago)

    I’ve seen this approach to making ollas and I like the simplicity.

    Are you concerned about the glue containing toxins and leaching into the water, soil and ultimately your food?

    • Kristina
      June 4, 2012 at 11:14 am (2 years ago)

      I’m sorry Michael – I just saw this comment. In the scheme of things, it’s a very small amount of glue so I’m not worried. I garden organically and don’t use pressure treated wood in my beds. They boost the performance of my plants so much that I think it’s worth the small risk.

  6. Sue
    February 21, 2013 at 8:51 pm (2 years ago)

    I plant vegetables in pots on my patio. Will this work in pots? I have had terrible luck with tomatoes, dill and sage. However, rosemary and thyme does very well.

    • Kristina
      February 21, 2013 at 9:04 pm (2 years ago)

      Rosemary and Thyme both grow in arid regions so they’re marvelous for pots. Sage should do well too. Before I’d try the ollas, I’d do this. First put your plants in as big of a container that you can find. It’s better to put more plants in big containers than plants in their own container. Use a saucer and when you water, water until all the dirt is soaked and water is coming out into the saucer. A coffee filter works well to keep potting soil from coming out. I also put a small amount of rocks in the bottom of each pot. Use a good potting soil. Don’t try to save money by buying the cheapest kind at Walmart. Ask for a good planting soil mix at your local garden center. I actually make my own since I have so many containers. Organic fertilizers are better than synthetic. You want your plant to grow slowly and steadily, rather than having lots of tender new growth all at once. Also see if your local garden center has a product like this: – use only the amount called for. It really helps a lot for container plants. Grow dill & cilantro from seed. Never buy plants. They just bolt and go to seed very quickly. Basil is very fussy. If it gets a tiny bit droopy, it’s really easy for it to succumb to disease. I hope this helps!

  7. Lesley Bryce
    December 4, 2013 at 8:18 pm (12 months ago)

    Thank you – just found this page by random. I am in SE Queensland Australia and these ollas look amazing. We come and go to this place and I’m always looking for ways to keep things going in between visits – although some stern words and good settling in period does amazing things in my Garden of Neglect! I’m working now on small pots I can place vertically, with cilantro – I use heaps of it but can’t get it to grow in anything but a very short season. I’ll browse your site. Vinaka


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