Irrigate like it’s 2000 BC with these easy DIY terracotta watering pots called ollas

Irrigate like it’s 2000 BC with these easy DIY terracotta watering pots called ollas

Make an Olla (pronounced oi-ya)

Ollas have been used for thousands of years in agriculture and gardening practices and are traditionally unglazed terracotta “jugs” filled with water and buried into the soil, with their necks protruding slightly. Once the porous terracotta olla is in contact with the soil, water begins to seep into the surrounding soil, directly to the rootzone of surrounding plants. The amount of water drawn from the olla varies depending on the soil moisture – dry soil will draw water faster; wet soil slows it down.

This is great in our dry, hot climate – there’s no water wastage through run-off and evaporation, the water goes exactly where it’s needed, and the risk of fungal issues on foliage is significantly reduced due to the foliage not being wet during a watering. The burying of the olla in the soil also promotes deeper roots systems that are better able to manage fluctuations in heat. Perfect! Ollas are brilliant in pots, garden beds and even adjacent to plantings of young trees, but they do have their downsides – traditional olla’s are hard to come by, don’t last forever and are prohibitively expensive. Luckily, there’s an easy way to make them yourself for next to nothing.

What you Need

Two equal sized unglazed terracotta pots. (Tino used 13cm which holds about 3lt of water when full
One tube of weatherproof silicone sealer. (Use a food-safe grade silicone for water tanks and indoor plumbing.)
Plastic milk bottle (or similar), cut to a disc to fit over bottom pot drainage hole. (This doesn’t need to be plastic, but needs to adhere and form a perfect seal with the silicone.)

What to Do

Using a plastic disc, seal the drainage hole on the bottom of ONE of the pots, inside and out to prevent leaks
Pipe some silicone around the rim of this pot, and then place pots on top of each other, making sure the rims meet and line up. Gently pipe silicone around the join and smooth around the seam
Allow around 24 hours for the silicone to cure and dry, and then test your olla for leaks by filling it with water…..

How to Install

Bury the olla in the pot or garden bed, leaving just a couple of centimetres and the open hole exposed. Its important to pack gently pack soil around the olla. Water will not disperse in air pockets and roots will not grow in air pockets.
Fill with water (use shower warm up water, rainwater, potable water) and cover the small opening with a saucer, stone or similar – this will stop the olla getting rubbish, mulch and mosquitoes inside.
The size of your cheap and cheerful olla will determine how far the olla will water – the smaller the olla, the less distance the water will spread. In good soils, expect the water to spread at least the width of the olla in all directions.
Keep an eye on the water level inside the olla, and depending on the weather, the soil and the size of your olla, expect to refill it every few days to a week.

Olla irrigation is brilliant in pots, so consider bunging it into the middle of your planter next time you replace your crops, and drop your seedlings in around them. Olla irrigation is most efficient for crops with fibrous root systems like squash, melons, watermelons, tomatoes, and chilies, but it can work well for establishing young trees. Bear in mind that tree roots can, over time, damage and even crack an olla, so keep an eye on them if they are emptying too quickly.

Speaking of emptying, is there an easy way to tell if your olla is empty? Well, yes and no – some canny crafty folks may use a float installed inside the olla with a flag out the top so they can tell easily (and from a distance) when their ollas need a refill. The less crafty amongst us can use an old wooden chopstick or skinny bamboo stake to see exactly where the water level is up to – or just have a good old look!

Ollas can be made in just about any size imaginable – from small to quite substantial. While there is some growing space taken up in pots and beds by the olla, the long-term benefits to plant and soil health through consistent watering is worth the sacrifice. A tip – make sure that the pots you buy to make your olla aren’t sealed…..the water needs to be able to leach out.

Take Home

Ollas are adaptable, portable and sustainable, and are a pretty good way to keep you soil healthy and your plants happy, especially your precious potted pretties or incredible edibles. And, as they say, everything old is new again – give this ancient irrigation technique a run at your place.

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  1. Gill Adams on September 15, 2021 at 11:02 pm

    My parents always used to put an unglazed terracotta drainage pipe (open both ends) next to each tree they planted. This was filled up to water the tree and “get the water down to the roots”.

  2. Michael Ripperger on September 15, 2021 at 11:06 pm

    My momma always told me no to stick my finger in bung holes

  3. Pond and garden sanctuary on September 15, 2021 at 11:11 pm

    great info

  4. Buggles on September 15, 2021 at 11:11 pm

    every Australian TV show ever: *HERE’S ONE I PREPARED EARLIER*

  5. Small Garden Quest on September 15, 2021 at 11:12 pm

    I making these this year 🙂

  6. BABO Home & Garden on September 15, 2021 at 11:13 pm

    Thanks for sharing great wisdom! Plan to try this out this season!

  7. Delsin071 on September 15, 2021 at 11:15 pm

    Finger in… "Wet." 😂😂😂😂😂

  8. Gissie on September 15, 2021 at 11:17 pm

    Cork stopper?to block holes?can try it out inndesert tree use big jars in trees olive groves dont need that much water any way.

  9. J Christ on September 15, 2021 at 11:17 pm

    Love that little joke you threw in there – even paused after. "Olla" have to do… lol

  10. John Walker on September 15, 2021 at 11:19 pm

    I’ve tried this with cheap unglazed clay/terracotta pots from Bunnings. BUT when testing by filling with water and leaving standing on the ground the water level remained unchanged even after a couple of week. In contrast a commercial Olla would drain in 24 hours.

  11. Javier Gutierrez on September 15, 2021 at 11:25 pm

    hola, interesante experimento lo pondré en practica en mis cultivos de tomate, un saludo desde Venezuela

  12. Moto's Allotment Garden on September 15, 2021 at 11:26 pm

    I made some terracotta pot olla’s and they work great

  13. Carmen Greer on September 15, 2021 at 11:28 pm

    Lovely garden.

  14. Nayda Klein on September 15, 2021 at 11:33 pm

    Omg. What kinda “finger” you mean/ 😂

  15. Bebo Rosa on September 15, 2021 at 11:34 pm

    Imagine sealing two pots with silicone in 2000 BC 😂

  16. Plants forever on September 15, 2021 at 11:34 pm


  17. Josip Marketanović on September 15, 2021 at 11:35 pm

    Thank you very much.

  18. Miss Lee on September 15, 2021 at 11:37 pm

    The music is distracting.

  19. Demidio on September 15, 2021 at 11:37 pm

    3:07 forget science
    this old fashioned method of checking the juices levels also dates 2000BC

  20. Jay M on September 15, 2021 at 11:37 pm

    Centimetres? Litres? What sorcery psycho babble is this?

  21. Combat Pyro on September 15, 2021 at 11:38 pm

    Or you could mulch the garden beds deeply

  22. Antifaz Antifaz on September 15, 2021 at 11:39 pm

    Hi My friend.. I had the same idea… I am from spain… the same size of pots… double volume… than traditional idea.
    Incredible… amazing… What a surprise so long… but so close.

  23. Doug Anderson on September 15, 2021 at 11:42 pm

    These need to be kept full to work properly, so check and top up regularly.

  24. crazy squirrel on September 15, 2021 at 11:44 pm

    I made one similar to yours except I added a fill tube and a float (float made out of old pill bottles) and a stiff metal rod.
    I attached a plastic butterfly to the top of the rod.
    Rod runs through a pvc cap that is easily removable.
    When the butterfly is high (flying) there is plenty of water.
    When the butterfly drops to the cap, it is ‘resting’ and needs more water.
    A cute setup – women like that stuff.
    One could use a flag but not as visually enjoyable.

    Also, some people use mortar mix in the bottom.
    Keeps the water from weeping out too quickly from the bottom.

    Reason for the PVC tube (it is actually PVC water pipe) is so I don’t have to bend over to fill them.
    Rule of thumb: bending over is bad, standing is good.

  25. Adam Walsh on September 15, 2021 at 11:47 pm

    Great video! Thank you!

  26. dragoncarver on September 15, 2021 at 11:48 pm

    so you gottta have a really long finger to tell when it’s almost empty. lol

  27. Sweet Woodruff on September 15, 2021 at 11:51 pm

    This hot Texan really appreciates this idea. My plants cook in the summer. Even heat tolerant plants wilt in August.

  28. Karen Meyers on September 15, 2021 at 11:52 pm

    Love this, my fist task for today to keep my frog habitat damp 🥰🐸

  29. Alice Mary on September 15, 2021 at 11:57 pm

    an excellent alternative to the hassle of diy-ing, is to buy un-glazed terracotta wine coolers. 9 time out of ten a second hand shop will have one.

  30. Keri Luiz on September 16, 2021 at 12:01 am

    I’m trying these with my tomatoes and herbs this year. Silicone didn’t work for me, the porosity of the terra-cotta made it fall off. Gorilla glue worked like a champ.

    Maybe I used the wrong silicone.

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