Introduction: DIY Irrigation Pots - a Modern Take on an Ancient Technique

Picture of DIY Irrigation Pots - a Modern Take on an Ancient Technique

Ollahs (pronounced 'oy-yahs') are traditional unglazed pots, which are sunk into the soil around the base of plants. The idea is simple, you fill the ollahs with water, which gradually seeps out through the porous container directly to the roots of the plant you want to water. It is an excellent technique because -

  • It reduces surface evaporation
  • It keeps plants constantly watered
  • It cuts down the time it takes to water your garden or allotment
  • It saves water

Here's a wikipedia page explaining them -

But ollahs can be expensive to buy, and if you can't find anywhere that stocks them then you'll have to commission a potter to make some for you. Or you could just follow this easy Instructable and make one for under $5.

Step 1: What You'll Need...

Picture of What You'll Need...

To make an ollah you will need some simple materials. These are as follows -

  • Two ceramic unglazed pots.These need to be the same size, and it is essential that they are unglazed. The ones I am using here are 13cm diameter pots, and cost me under $1 at the garden centre.
  • A small ceramic saucer. This needs to be able to sit into the bottom of the pots you've selected. In order to do this I bought the smallest available. It isn't essential that it is unglazed.
  • Some glue.I'm using UHU Max Repair Extreme, because it is waterproof, flexible and suitable for unglazed terracotta.

Step 2: Seal the Hole in One Pot

Picture of Seal the Hole in One Pot

The first thing you have to do for this Instructable is to seal the hole at the bottom of one of the pots. The reason that you do this is simple; if not, all the water is going to run out too quickly and the ollah becomes useless.

Put glue around the bottom of the saucer, and be very generous with the amount you put on. Invert it, and then place it in the bottom of the pot.

Step 3: Put the Two Pots Together

Picture of Put the Two Pots Together

Once a hole is sealed at the bottom of one pot, spread glue around the top edge of that pot. Again, be generous with the amount you use - it doesn't have to look nice, it has to be watertight.

Now invert the second pot so that the top edges of both come together. Spread additional glue around the join to reinforce it.

Step 4: Let the Glue Dry

Picture of Let the Glue Dry

Now is time to congratulate yourself on a job almost done. Put a couple of heavy books on the pots, and leave to dry. In the meantime, have a cup of tea, read a book, learn how to play the ukulele or do something else entirely.

Step 5: Dig a Hole

Picture of Dig a Hole

Once the pots are glued together, and the glue is dry, dig a hole in the ground or the pot that you wish to water. I am planting my ollah into a 80l pot which contains an apple tree.

I live on the 8th floor, with a roof terrace that faces due south. Sometimes the pot dries out completely between me watering it in the morning and evening (it's 35degrees celsius in the summer here). The fluctuation between wet and dry puts stress on the tree and that's one of the reasons we've had few apples from it this year. With constant watering from the ollah, the apple tree will hopefully have a happy summer.

In order to sink the ollah you want to dig your hole almost as deep as the pots are tall. Sink the ollah into the hole, and leave about 3cm or 1inch above the soil line. I've also added bark chips to the top of the soil, because it makes the pots look a bit neater.

Step 6: Fill It Up!

Picture of Fill It Up!

Now all that is left to do is fill up the pot. My ollah holds about 1.5l of water, which means that in the height of summer I will most likely have to fill it up every day. However in the spring and autumn it will be good to be left a week between filling it up.

Step 7: Things to Remember...

Finally, there are a few things you want to remember if you are planning on using ollahs to water your plants...

  • Don't let them dry out completely. This can be bad for your plants because it leaves them without water, and because the ollahs can build up salt and residue from the water you use. As a rule of thumb try to keep some water in them at all times.
  • Remove them before the winter if you get ground frost. If your ground freezes then the pot will crack and be useless next year.
  • If you are making pots smaller than this one, its a good idea to put a stone over the opening at the top which will help with surface evaporation.

Thanks for reading this Instructable and let me know how your garden gets on when using them. You can follow my garden adventures at





; D

HelenaTroy (author)2016-08-03

I use a plastic drinks bottle, size depending on size of pot, with a tiny hole at the bottom, and bury it as I pot the plant. The problem is to make the hole small enough for the water to drip-seep out, not gush! I did think of using wicking material to lead the water all around the plant, but not got round to that yet. The screw lid stops the water evaporating from the top

Schnelly B (author)HelenaTroy2016-08-03

That is a good idea, but do you find that the roots all concentrate around the one hole?

girlcousin (author)Schnelly B2016-08-08

I just upend the full bottle and let it leach out into the soil

HelenaTroy (author)girlcousin2016-08-09

I also water from the top, but with bigger plants in bigger pots, or even in the ground, I wanted to make sure that the roots got plenty too

HelenaTroy (author)Schnelly B2016-08-04

I haven't noticed any clustering, not that I thought to look for any but I'm sure I would have noticed if there'd been any. Maybe because the hole, though as small as I could make it, was still too big, the water spread right across the pot, rather than seeping in one place.

I do like the idea of using pots as in this Instructable, but I try to take up as little space as possible - even with plastic bottles, I found I was having to use a pot larger than the plant size warranted, to get the bottle in without crowding the plant.

Simplest one I've tried so far is a length of plastic tubing buried when potting, a couple of inches above the surface so water can be tipped in.

Marcos Baldin (author)2016-08-02

Great idea.

My only concern is related to using it in tropical countries, where mosquitos are vectors for dangerous diseases. They like laying eggs in clear water under dark places.

But I think it's just a matter of keeping a cork closing the pot hole.

billbillt (author)Marcos Baldin2016-08-02

Or you could tape/glue a piece of window screen on it to cover the hole..

Marcos Baldin (author)billbillt2016-08-06

Good idea. ;-)

Schnelly B (author)billbillt2016-08-02

Yeah, I'm in Switzerland so I don't really need to worry about these things, but a plate, cork or stone would all keep the critters out.

FergusK (author)2016-08-02

Very nice. Im a fan of diy sub irrigation which might be a slightly better method. Or might not be! Yiu can find my description here:

Schnelly B (author)FergusK2016-08-03

That's a great idea, thanks for sharing.

FergusK (author)Schnelly B2016-08-05

Pleasure. Not my idea originally but one worth sharing.

Spindlebender (author)2016-08-04

Tremendous. A nursery near the home markets terra cotta waterers with a similar effect, the reservoir being an inverted 2 liter PETE beverage bottle. I've several potted citrus plants which would benefit from continuous watering, but NOT at the $19 each for the small clay fixture. Three unglazed pots + drainage tray + sealer adhesive; now, I can buy that. Thank you, and my citrus plants thank you, too.

Schnelly B (author)Spindlebender2016-08-04

$19 each!! That's exactly why I thought this up... that's a crazy amount of money.

If you are making a few though, have a chat with the nursery. Mine was happy to offer me a bulk deal because I basically bought so many at once. I made a load for my mum and they came in under $3 each!

Banzai Beagle (author)2016-08-04

Where can one find UHU Max Repair Extreme in the US?

Schnelly B (author)Banzai Beagle2016-08-04

Use silicon sealant, it will work just as well as it has all the properties you need - flexible, waterproof and sticks to unglazed pots!

Banzai Beagle (author)Schnelly B2016-08-04

Thanks for the tip!

Schnelly B (author)Banzai Beagle2016-08-04

No problem.

travlinjohn (author)2016-08-02

I would fill the completed ollahs with water and measure the time it takes to empty. This will help you to maintain a healthy amount of water in the planting. Over watering is almost as bad for plants as under watering. Adding Mulch to the pot or any planting is a very good idea. The practice helps to reduce evaporation and adds nutrients to the soil as well. Mixing your fertilizer in the water makes that process easier also.

Schnelly B (author)travlinjohn2016-08-04

Good ideas!

Schnelly B (author)travlinjohn2016-08-04

Good ideas!

mwitherspoon (author)2016-08-03

Very cool idea. You could add a plug to keep out the bugs and serve as a water level gauge.

One tapered cork fit to plug the hole in the Ollahs.
One smaller cork to pass through the hole in the Ollahs.
One drinking straw.
One bamboo skewer.

Drill a hole in the larger cork sized to the drinking straw. Slide the straw through, trim flush. Add a spot of glue if its loose. This acts as a bearing surface for the bamboo rod.

Slide the bamboo rod through the straw and poke it well into the smaller cork.

Insert this assembly into the hole in the empty Ollahs. Allow the inside cork to rest on the bottom of the Ollahs. Mark or trim the bamboo rod as desired to indicate the empty state. You could add even more marks to indicate various levels if your so inclined.

Fill the Ollahs with water. Insert this stopper/level gauge. The inner cork should float and shove the bamboo rod up indicating the level of the water.

DavidB560 (author)mwitherspoon2016-08-03


Schnelly B (author)mwitherspoon2016-08-03

Whilst this is a great idea, it feels a little over engineered for my liking.

I just use a little torch to peer inside and see the water level, and if in doubt wander round with a watering can, topping up as I go around the roof terrace.

But I applaud you ingenuity, I just don't have the time to do this for 30+ ollahs!!

mlaiuppa. (author)2016-08-03

Brilliant idea. I've seen Ollas but always stayed away because of the obscene prices. This is a brilliant hack.

I would use silcone glue as I've repaired several broken glazed pots and they haven't fallen apart yet.

Could you glue a smaller pot on top as a neck or funnel? That way you could bury the large part of your Olla even deeper.

Schnelly B (author)mlaiuppa.2016-08-03

I hadn't though of using a smaller pot as a funnel, but I don't see why that wouldn't work.

And yes, silicone glue or sealant will work just fine. Make some and let me know how you get on!

slippyblade (author)2016-08-02

Considering the ridiculous price of a real Oolah, this is absolute genius. These little pots are dirt cheap and the concept is amazingly simple. I never would have thought to do this, thank you!

Schnelly B (author)slippyblade2016-08-02

I'm so pleased to hear this! Go, make hundreds of the things and grow loads of beautiful plants!

slippyblade (author)Schnelly B2016-08-02

I live in Phoenix, and keeping the plants watered decently is a challenge. I'll be doing exactly this over the weekend. I'll try to get a couple pics.

Schnelly B (author)slippyblade2016-08-03

Please post any pictures, I would love to see how you get on.

rbormann (author)2016-08-02

One word. Genius.
A few more words. Here in Brazil, it is very common to find at outback farm houses a water pot, called moringa, that is known to keep the water fresh due the porous walls and consequent water evaporation. I guess i could use it ready to achieve the same results. What do you think?

Schnelly B (author)rbormann2016-08-03

Yeah, that sounds like a great idea. Give it a go and let me know how you get on.

charlesd.parker.33 (author)2016-08-02

Thank you for sharing.

No problem. I hope you find it helpful.

Terry Van Kirk (author)2016-08-02

Where did you purchase the glue? Although it's possible to purchase it from Great Britain and a myriad of other countries, I haven't been able to find a source in the U.S.

UHU Max Repair Extreme

I bought the glue in Switzerland, however you don't need to buy the exact same UHU Max Repair Extreme. In fact, as long as it is a flexible, waterproof glue, that adheres to unglazed ceramic then you should be good to go.

Someone below mentions that you can use silicon sealant. My neighbours have tried this a couple of times and it has worked out well. I just avoid that because the glue is cheaper than the sealant here, and I can buy it in smaller quantities.

808Dave (author)Terry Van Kirk2016-08-02

I wouldn't get hung up too much on getting the exact brand. Many glues work fine on unglazed ceramics - check their labels. Personally I'd try silicone sealant (test a batch to be sure it sticks OK, though - and only on dry ceramics) because I've already got it around in caulking-sized cylinder-tubes. (It's often used as the SOLE structural adhesive holding the glass for aquaria together, and that represents very large forces.) What the author is using looks like a UK version of good-ole "Duco cement," aka "vinyl cement," aka many other brand names.

YahyaAA1 (author)2016-08-02

All this talk about keeping the bugs out ... and then you glue the pots together under a couple of "slaters"! (That's what we call woodlice in Australia ... ;-) )

Anyway, your ollas are heaps cheaper than buying them ready-made - a brilliant idea!

doing2much (author)2016-07-24

Nice, simple and 'do'able solution to a common problem - especially in California... I commend you for your spirit of gardening on the rooftop, especially with fruit trees like apple, which do not like too much sun! I voted for you :)

Schnelly B (author)doing2much2016-07-25

Thank you for the vote, that's very kind of you...

And yes, growing fruit trees on a balcony is a bit of a challenge, but it sure is fun!

DavidM15 (author)Schnelly B2016-08-02

I take it you are growing Dwarf fruit trees ?

Schnelly B (author)DavidM152016-08-02

One is a dwarf, and the others, well, got mis-sold by the garden centre! They should be but they aren't... whoops!

DavidM15 (author)doing2much2016-08-02

Really, Apple trees don't like the sun??? I guess that you never been to the orchards in either Hood River or in Yakima. Both areas receive many many days of sunshine. Yakima gets over 300 days of it a year. Both Hood River and Yakima are known for their apples.

The Kiyokawa orchard in Hood River, has been growing Apples and Pears since 1911 - "We're proud to be a part of the famous Hood River Valley, where the nation's finest apples and pears are grown."

and of coruse Yakima Apples

ShawnS60 (author)2016-08-02

This is quite the beautiful idea; thank you. Now you're my therapist if you read further...we moved this past year, coming up on 2 years, really. I grew a LOT of pots where we were; I always had a few going, something going on. I try here in the new place, but I just haven't put in the effort this year. We have had several deaths in the family. I know. Gardening helps that, so it's no excuse. We've been on so many trips (see above excuse) that I left a soaker hose on a timer for the tomatoes and chile peppers, and they are alive. OH! And my lantana in the ground, and one lavender, again, in the ground. They're all alive.

But we haven't been getting the tomato harvest we ought to have, nor enough hot peppers, but we've gotten a few jalapenos & serranos (they're almost too hot to eat :-) Happy face.

I will try your ollahs, and keep my potted Geraniums and petunias alive next year. Thank you again!

Schnelly B (author)ShawnS602016-08-02

Happy to make the suggestion and to be the therapist ;)

But seriously, gardening has got me through some dark times and so if you do feel up to it, get out there and get your hands dirty. If not, the ollahs will buy you some time until you feel more up to it.

j1shalack (author)2016-08-02

Super idea... You can test the water depth by inserting a straw to the bottom, put your finger on the top, and withdraw straw to view water depth. Or, insert a wood skewer like a dipstick.

Schnelly B (author)j1shalack2016-08-02

Great idea!!

bookemdanho (author)2016-08-02

Does this promote uneven growth since most of the water is to one side of the plant's roots? Won't the roots migrate towards the water/ollah?

Celg (author)bookemdanho2016-08-02

The dry soil will wick the water across the pot faster than the roots grow, so it should not be a problem. I would give the entire plant a good watering after burying the ollah.

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