Mark Valencia has been growing food on his 3-acre Queensland homestead for years. He's skeptical by default. So when he heard that burying clay pots underground could cut his watering time and produce bigger vegetables, his first reaction was: sounds impossible.
Six weeks later, he was pulling up cos lettuces he described as the largest he'd ever grown — and holding them next to hand-watered ones from the same bed to show the difference.
This is not a sponsored review. Mark bought the kit himself and documented the whole trial on his Self Sufficient Me YouTube channel. Here's what he found, why it worked, and what he'd do differently.
▶ Skip to 6:30 for the side-by-side lettuce comparison
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What Is Olla Irrigation, Exactly?
The concept is ancient — originating in drier parts of South America, North Africa, and Asia where water was scarce. An olla (pronounced roughly "oy-ya") is a porous clay vessel buried underground near plant roots. Water seeps slowly through the clay walls directly into the surrounding soil, where roots absorb it as needed.
What makes it clever is the self-regulating mechanism: if the surrounding soil is already moist from rain, seepage slows to almost nothing. If the plant is actively drinking, flow increases. The clay acts as a passive valve driven entirely by soil moisture and root demand — saving water and preventing overwatering at the same time.
There's a root behavior effect too. Plants watered from above tend to develop shallow, horizontal root systems. Plants drawing from a buried olla push roots downward in search of that water source — building drought resistance and structural strength over time.
"Because the water is distributed underground, less is lost through evaporation. And root systems grow down further, which helps drought-proof the plant." — Mark, Self Sufficient Me
What the Modern System Adds
Traditional ollas are individual pots — each one needs to be refilled by hand. The Thirsty Earth system connects multiple ollas underground with irrigation tubing, all feeding from a single reservoir. Fill one container, and the whole bed stays topped up automatically.
For a 4×8 raised bed, that means nine clay cylinders working in parallel from one bucket. Mark noted that installation took about 30 minutes start to finish: lay out the ollas, dig or auger the holes, push the fittings together, fill the reservoir, and done.
What Actually Happened in Mark's Bed
Mark planted salad seedlings and ran the system for six weeks. Aside from a few rainfall events, the bed received water only from the olla reservoir — which he refilled just four times total. For context, he typically hand-waters more often than that.
Results varied by position. Plants near the center of the bed, flanked by ollas on both sides, grew the fastest. Plants near the edges — further from any single olla — lagged behind. One olla had cracked in shipping and was bypassed; the plants in that zone showed the deficit clearly.
The headline result comes at 6:30 in the video: Mark pulls a cos lettuce (commonly known as romaine lettuce) grown under the olla system and holds it next to one he hand-watered over the same timeline. The root system is visibly larger. The overall plant is noticeably bigger. He calls them the largest cos lettuces he's ever grown.
"I think the reason for this exceptional growth was the constant, uninterrupted access to water." — Mark, Self Sufficient Me
His theory: consistent low-level moisture lets plants grow steadily without cycling through wet-dry stress. Think of the thick, lush grass that grows around a dripping outdoor tap while the surrounding lawn dries out in the heat — same principle happening underground.
Who This System Works Best For
Mark is direct about where ollas shine most:
- Raised salad and herb beds — consistent moisture prevents bitterness and bolting
- Smaller urban gardens, balconies, and courtyards — less hand-watering, less mess
- Containers that dry out quickly — especially through hot summers
- Newly planted fruit trees — steady moisture while they establish
- Beds where you fertilize heavily — water seeps in rather than flushing nutrients out through the bottom
That last point is worth noting: because moisture seeps laterally rather than flushing through from above, soil amendments and fertilizers stay in the root zone instead of washing out.
A Few Honest Caveats
Two of Mark's eleven ollas arrived cracked — likely rough handling in transit — leaving him with nine for the bed. He estimated that wasn't quite enough for full coverage on a 4×8 bed and would recommend 12–15 ollas for no dead zones. (Note: Thirsty Earth recommends 12 cups for a 4x8 bed. Also, if any of your cups arrive broken in transit, contact us for replacements.)
Olla spacing matters a lot. Coverage averages 18 inches from center, with best absorption in the inner 6–12 inches. Space plants or ollas too far apart and you'll see the difference in growth — exactly what Mark observed along the bed edges closest to the bypassed olla.
For very large properties with many beds, the cost adds up. Mark sees this as a targeted tool rather than a whole-property solution — most effective where precision and water efficiency matter most.
The Bottom Line
Olla irrigation isn't magic — it's physics. Porous clay, root demand, and soil moisture doing the work. What the modern connected system removes is the biggest practical friction of the traditional method: refilling individual pots. One reservoir, multiple ollas, and your bed waters itself between rain events.
Mark's six-week trial is a solid real-world proxy. Fewer refills, bigger lettuces, deeper roots. For a salad bed, an herb garden, or a balcony container setup, the evidence is hard to argue with.
Ready to Try It?
Save Water. Grow Bigger.
Kits are sized for standard 4×8 raised beds and include everything needed. Most gardeners are up and growing in under an hour.
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Video Transcription:
Note: We've revamped our packing since this video was filmed.
00:00 Introduction
Water is sometimes scarce and it's for sure becoming more expensive. So that's why I decided to try this new ancient way of watering plants and saving water at the same time, by letting your plants drink as much as they need.
I know it sounds impossible, and you might think that I don't know manure from clay, but that's what this olla watering system promises.
But does watering through clay cylinders really work? Good day, I'm Mark from self-sufficient me. In this video, I'm going to show you my olla watering system and give you my thoughts on whether this medieval way of watering through clay really does work. Let's get into it.
For those of you who don't know, olla basically means hello in Spanish. I'm joking. Hello is hola.
Olla means pot. I mean, I would've pronounced it El Poto, but then my Spanish isn't very good even with the last name Valencia. Anyway, I digress.
The olla way of watering plants came from South America and probably North Africa and drier parts of Asia where water is scarce. It makes sense.
The olla watering method is based on water slowly seeping out of a porous clay pot that has been buried in the ground. The root system of a plant or plants grow near the clay pot and the water is used by the plants. More water continues to seep out of the pot until it's empty and then it's refilled or topped up.
But the cool thing is if the plants aren't using that water or if the outside soil is wet, say from rain, well limited amounts or hardly any water will seep out. It'll virtually come to a stop.
So this natural mechanism saves water and prevents overwatering. And because the water is distributed underground, less water is lost through evaporation.
Also, root systems tend to grow more horizontal or shallower when you water by hand or top water. Whereas the olla watering system encourages roots to go in search of that water and grow down further, which helps to drought proof the plant.
It also gives it more strength and stability overall. Traditionally, ollas are individual clay pots strategically positioned in the ground. But Eric, the founder of Thirsty Earth in Utah, contacted me and introduced me to this olla watering system, which links pots together with irrigation piping, allowing for a group of ollas to automatically refill from a single main reservoir. So essentially, you only fill up one container instead of several, and that saves a ton of time.
(03:07)
I thought these clay pots linked together was an interesting step up from the individual ollas so I purchased a kit to try for myself. I didn't get the kit for free. This video is not sponsored and there's no affiliatization. I just really wanted to try them out and see if it's as good as Eric said they were.
The kit I got was for a raised bed four by eight feet, or 1.2 meters by 2.4 meters, which is exactly the size of this bed here. The kit included hoses, fittings, a water storage container, and I also got an auger, although I'm not sure if that was part of the kit or an extra Eric threw in. Unfortunately, I found two of the ollas were broken or cracked during transit. I suspect the package delivery guys played soccer with the boxes. I mean, it's leading up to the World Cup here in Australia. So who could blame them? I mean, it's not their property, so why should they take care of it?
So anyway, I ended up with 9 ollas instead of 11 in this bed, and I'll talk about that shortfall later.
Installation was simple. The instructions were easy to follow.
I already had a raised bed with various salad seedlings planted out. The first thing I did was put a tile down as a stable base for the water container.
As I said, when I was unpacking the ollas, I found that one was obviously broken, so I put that aside and laid the rest as evenly spaced as I could. I got you on the reverse angle. According to Thirsty Earth, the water spread or plume averages about 18 inches from the center of the olla with the best coverage 6 to 12 inches. Therefore, you don't want to position your ollas or plants too far away from each other obviously, or it won't work.
(04:56)
I then placed the fittings down to make a closed loop from the watering container and installed the first piece of irrigation piping with the off tap onto the base of the bucket. After that, it was time to bury the ollas and I used an auger to drill out the holes, but it would've been easy enough to dig them in by hand to be honest, using a drill and auger was fun though.
Connecting the fittings and piping to the ollas was no trouble. All the parts just pushed together and within about 30 minutes, I had the whole system assembled.
The last thing to do was to fill up the storage bucket, and with the tap turned on, it was up to the olla watering system to start seeping.
Not long after I noticed that the reservoir was losing water really quickly and on further inspection, I realized that another one of the ollas had been damaged with a vertical crack going down the cylinder.
(05:48)
So I ended up bypassing that one. And as you can see, I've left it in here. But the other thing you can see is that the plants around this one here that's not producing water aren't growing too well at all, and that's because they're far too far away from the other ollas.
And speaking of water, apart from the beginning when I first planted these seedlings out, the only water that this bed has received is from rainfall and the olla system.
Over the past six weeks, I've had to fill the reservoir up four times, which is better than once a week and a lot less than if I was watering by hand, as I usually do.
Overall, most of the plants in here, as you can see, have grown exceptionally well. I mean, just have a look at these massive cos lettuces here. I mean, they're incredible. These are the biggest cos that I've ever grown.
I mean, compared to these here that I have watered by hand and have grown at the same time, you can see the difference. I mean, they're growing good, but nothing like over there. I think the reason for this exceptional growth was because of the constant access to water. I'll pull this out.
(07:18)
Look at the size of the root system. Now, that's massive compared to the other one, and that is a lot bigger.
But the extra water it's getting and the constant access to as much water as it needs,
I've got a theory. It's a bit like … have you ever seen on at a school yard where there's a leaking tap and underneath that leaking tap, you've got the grass that grows thick and tall and lush, and then the surrounding grass might be dry and withering away in the heat. That's what I'm talking about in contrast.
See this strip here of lettuces are quite small, and I think that is because they are too far away from the ollas. And the other thing is this middle strip here that are all lush and big have ollas on either side. So they're getting twice as much water as the one on the side here that only gets it from the one side.
(08:23)
So what's my verdict on this olla watering system by Thirsty Earth? Well, I'm a hand waterer by trade. I like walking around and spot watering our plants, so it's rare for me to utilize any watering system at all anyway.
Plus we have a large veggie garden and it's just not cost effective to use this system in every garden bed.
I found in this example that the closer your plants are to the olla, the more water they will get. Yeah, duh. But I also found that nine ollas in here because two were broken, weren't quite enough to do this full bed. And I reckon you'd want around 12 to 15 to water this bed perfectly.
(09:10)
So buying extra olla kits could become cost prohibitive for most people. If you have a look online, some olla pots and boutique designs are very expensive, and although you could make your own olla out of a couple of terracotta pots or just one terracotta pot, plug up the hole, pour water in it much cheaper. It's still not a very practical way to water.
But I do intend to trial these ollas in smaller containers and pots because a problem I do have is my smaller to medium sized potted plants drying out too quickly or I forget to water them daily, especially during our hot summers. Say one olla per small pot linked to the bucket could work really well.
Which brings me to who or what would this olla system be most useful to and for? I think if you are living in the city, perhaps a balcony garden, those growing in smaller spaces, a tiny courtyard, they could use this system to both save time watering by hand, but also make less mess through water spills due to spilling over or excess water washing through the container and out the base.
Speaking about washing through the container, another plus for water just seeping into the garden bed or seeping into a pot is that it doesn't wash through or rinse out all the nutrients and fertilizer. A lot of fertilizers and nutrients are washed through the pot and just out onto the ground because of the water going through it. But this seepage system that negates that.
In a bigger backyard, this system could be used to grow specific crops that you really want to ensure it gets the water it needs.
A salad bed like this one or a bed full of annual herbs like basil or coriander, especially in warmer climates, work well because you want crispy lettuce and plump herbs to get all the moisture they need without getting stressed. Because as we know, stress salad and herb crops taste bitter and they go to seed faster.
And lastly, olla watering can be effective for newly planted fruit trees. They usually need to be watered regularly, if not daily, before it is established enough to survive. So using an olla could be a good way to ensure that the fruit tree gets off to a good start.
Anyway, if you have any questions or experience good or bad with ollas and you want to share it, whack it down in the comment section below so we can all learn from it. I hope you enjoyed this video. I'll leave a link to Thirsty Earth down into the description below and also the comment section. I'll pin that to the top, but if you did enjoy it, make sure you give it a big thumbs up and share the video around, subscribe if you haven't already. Thanks a lot for watching.
Bye for now. Cheers.
That's pretty impressive. It certainly is. Hey, thanks for hanging around. I got a little bit more intel on how you pronounce this olla thing. It's actually pronounced, I believe O like oi after the English cockney. Oi, come over here oi and ya. After the YA Swedish backpacker says yes in English ya. Anyway, I'm probably going to keep pronouncing it Ola, because I pronounce just about everything wrong and it won't be the first thing I pronounce wrong, and it won't be the last. Cheers.
You can visit Mark's website here: https://selfsufficientme.com/