Buried Clay Pot Irrigation: Low Maintenance Solution

If you are looking for ways to reduce water usage this summer (and low maintenance watering), buried clay pot irrigation might just be the trick you’re after. It’s a new concept to me but this method has apparently been around for centuries yet still offers value to today’s gardener. Here’s a bunch of info to get you started and then I added several different DIY irrigation methods at the bottom (some simple and small enough for house plants while others are more suited for gardens and shrubbery). Enjoy!

Use Vessels That Are Unglazed For This Project

Here’s the scoop: The idea is to bury clay pots (Ollas) in the ground making sure to keep the mouth level with (or just above) the soil surface and then fill them with water.

As the soil dries, suction develops and the water slowly seeps out from inside the pot and into the soil around it (the suction force is created by soil moisture tension and/or plant roots themselves, source). This is a naturally automatic system, if it’s been raining, the soil is wet so there is no moisture tension and the pots don’t release any water. The soil gets just what it needs, right when it needs it with no gadgets or sensors required!

Arrange the pots in clusters and plant your garden around them. How many do you need? Each pot will water the plants within its immediate area (responding to the soil moisture tension around it). The larger the pot you use, the larger the area it covers (and the less often you have to top it up with water).

Since the pots are buried, water is delivered more efficiently at root level rather than above the soil surface (with water needing to travel a few inches down to reach the roots). To keep the system working optimally, add more water to the pots as needed and avoid letting them dry out completely. Dig the pots up at the end of the growing season to prevent breakage over cold winter months. This method can be used in container gardening as well, you’ll just need to use smaller clay pots that will fit inside the containers or planter boxes leaving enough room for the plants to thrive.

What kind of pots to use: They need to be unglazed clay pots (otherwise the water will be sealed inside and won’t seep out) and can have a wide or narrow mouth. Select pots that don’t have a long or fragile neck so they’ll withstand being buried without breaking. You can use regular flower pots but make sure to seal closed the drainage hole. Keep the mouth of the jar covered to prevent insects and debris from getting inside and to help reduce water loss through evaporation. If there are no fitted lids for the jars, you can use flat rocks, shells or ceramic tiles depending on the size of the hole.

a clay pot in operation when installed neck-deep into the ground and filled with water...Source: upetd.up.ac.za (pdf)
A clay pot in operation when installed neck-deep into the ground and filled with water. Source: upetd.up.ac.za (pdf download)

Tip: To test whether a pot will work or not, fill it with water and watch if the surface becomes damp. If it does, it’s porous enough.

Bonus: Because the soil is kept moist inches below the soil surface, this helps reduce the growth of weeds (also means less water consumption and less maintenance).


Buried Pot Surrounded By Plants From ecocomposite.org

Here are some reference pages with more details (also make sure to grab the 25 page pdf linked to in the diagram image above)…

ecocomposite.org: Provides a bit of history to this technique and traces it back to over 2,000 years ago (from China). Also gives brief details of how it works and compares its results to other irrigation systems.

Olla Irrigation: (Clay Pot System) Lots of information on this page including a tip to add liquid fertilizer to the water (you’ll need just a quarter to half the amount you would normally use). They also show a DIY using regular clay flowerpots attached to each other using waterproof Gorilla Glue and silicon caulking. They advise painting the top of the Olla with white paint to reduce evaporation (top part of the jar will be exposed to the sun).

More Ideas

Is this clay pot method too much for what you need? Check out these ideas…

Automated Drip System: You don’t need to know much about hardware or plumbing, nor do you have to dig any trenches.

After setting up the head, you simply lay 1/2 tubing down and stake it where you’ll want to irrigate. Any place where you’d like to add some water output, you simply puncture the tubing with a specially designed tool, leaving a clean hole.

System is flexible, pretty much leak-proof, and go together like a box of legos.

Coke Bottle Watering Globes: The idea is to fill glass bottles with water and stick them neck down into moist soil. The soil seals around the bottle opening and water releases only as the soil dries. You can use larger bottles (for example wine bottles) if you need more time between refilling.

Here’s a similar idea using 2 liter plastic soda bottles from yougrowgirl.com. This places the bottle neck down as well but has the bottom cut off so you have a large funnel to work with (and collects the rain water too).

Iowa Watering Hole Trick: Keep trees and shrubs watered by drilling a hole in the bottom of a 5 gallon bucket, place it near the trunk and fill with water. This will slowly release the water into the soil, reducing the need for soaker hoses.

Supplies needed: A drill with 1/4″ bit, 5-gallon plastic bucket and a hose to fill pail with water.

To keep debris out (and potentially clogging the hole), cover with a piece of board.

DIY Bucket Drip: This is a gravity system to feed your drip irrigation system. A heavy pail and a few parts are required, but it’s fairly simple to setup.

Advises that if your bucket is too transparent, the light will encourage the growth of algae so choose a pail that’s dark and won’t let much light in.

Also gives the tip to choose a sturdy object to elevate the bucket since once filled, it’s darn heavy (5 gallons is about 33 lbs.).

Houseplant Wicking System: The idea is simple yet brilliant: feed water from a bowl underneath (or beside) the plant into your plant’s soil using strips of cotton fabric.

There are two different arrangement examples provided. Very simple way to keep your plants happy and avoid drying out.

This project was previously featured on Tipnut and moved here for better organization.

Wine Bottle Waterer: A simple setup using a wine bottle, wire from a hanging candle holder (or other hanger) and glass flat-backed marbles (to help get the drip right).
Plastic Milk Jug Ollas: Instead of using clay jugs, try this cheap version using plastic jugs instead. Several holes are drilled into the plastic (advises filling containers with water, freezing and then drilling) then the jugs are buried into the soil (same idea as discussed in the article above). Fill with water, twist on the cap and then refill as needed.
Simple Watering Wells: These are made by recycling plastic plant pots (one gallon or half-gallon sizes), bury them in the ground (keeping the rim just above ground level) and then filling with rocks. The water will slowly drip out through the holes at the bottom. Neat idea that’s a lot less expensive to put together than the clay pot method mentioned at top.
Make Your Own Ollas: Here’s another clever & cheap DIY, two terra cotta pots are attached to each other with Gorilla Glue then sealed on one end. Bury in the ground, leaving a couple inches above ground. Water is poured into the top hole (that wasn’t plugged).

Related Posts

How To Build A Fire Pit - Tips & DIY Resource Guide Simple & Functional: 15+ Ways To Make A Trellis


    • Linda

    It is misleading to say the larger the pot the more plants it will water. The area that will be kept moist from a wicking pot is a function of the soil’s ability to wick water. A peat based potting mix will usually wick about 4″ from the source whether a 4″ pot or 12″. If the soil is a heavier clay base then it will wick much less. Most successful wicking based system are raised beds using some form of Mel’s mix which is 1/3 peat, 1/3 compost and 1/3 vermiculite or pearlite.

    If you use sealed pots hooked up to an irrigation system then your are better off using a smaller pot. The only reason to use larger pots is if you are manually filling them. The advantage is a 4″ pot and saucer costs about $1.40 US a little silicone and tubing and a t fitting it runs about $1.50 to 1.60 per pot which Is fairly inexpensive. I keep mine filled using 5 gallon buckets gravity fed to the pots.

    • Jo-Anne

    I did the lazy-man’s ollas for my potted vegetable garden of about 15 x 45cm pots…with good success.

    My ‘ollas’ are a single terracotta pot about one third the size of my container [measures at diameter…] placed upright, with the hole at the bottom plugged and the matching saucer on top as a lid to avoid evaporation or breeding mosquitoes or dead vermin or leaf litter or or or…

    It is all too easy to lift the lid/saucer to check and fill with water as needed…and…I just add the fertiliser to the ollas/pot and replace the lid. I am testing what adding epsom salts to the ‘ollas’ will do to the terracotta.

    Bonus: As they are v-shaped I can easily remove the ‘ollas’ for checking and cleaning. I fill the lid/saucer with water for the birds and the bees. I have yet to glaze the lid/saucer and the rim of the ollas/pot to minimise evaporation even further.

    As a trial I plan to put a large terracotta saucer inside the bottom of one of the big plant pots so as to retain more water similar/not similar to a wicking garden bed…fingers crossed the soil at the bottom won’t go ‘off’…we’ll see.

    • claire

    To keep small animals from falling in and drowning 🙁 – cut a piece of screening 3″-4″ in diameter larger than the jar hole, fold down all around the top of the lid & secure it by wrapping a piece of wire over the screen and the lip.

    • Judy

    I have always had a large herb garden. Would like to now plant single type herbs in individual terra cotta pots and have them buried in the ground with only the top rim above ground. We live in Florida so having the ground freeze is remote. Does this sound plausible??
    thanks your advice.

    • Sergio

    I have a back yard with poor to mo drainage in a rainy country. Would this method allow the ollas to collect the excess rain water and to release it when needed? It certainly looks like an option.

    • Tandis

    I did this method last year but will definitely change to the milk jug WITH COVER idea. Last year a mouse fell into my clay pot, couldn’t apparently get out, drowned and began rotting in my pot. =/ Since the pot was a narrow top opening I didn’t see it and when I did see something there I thought it was a leaf and didn’t investigate. It was reallllllllly nasty! So I totally suggest some sort of lid. It did a nice job of keeping my tomato plants moist but not soaked or bone dry which was awesome.

    • Jean

    The link to the 25 page pdf did not work for me.
    Otherwise, this looks like a good idea! My soil is quite sandy and watering and irrigation never seemed to help. I would combine underground watering with composting on top. I think I will implement this come spring!

    • PH

    I live in the northeast and would love to use this method. If I were to use this method, I’d use a fairly large pot, but don’t want random holes in the yard during the winter, can the pots stay buried year round?

      • Tipnut

      Hi PH, I wouldn’t but then my winters are freezing cold here and the pots would crack for sure. You could refill the holes with dirt as you take them out. It takes just one crack in the pot for this to no longer work, water would seep out steadily. If you think your winters might be warm enough, try leaving one pot in the ground over the winter and see what happens.

    • Becky Stancill

    What a brilliant idea! A bit of cheesecloth and then a rock on the opening would really keep junk and bugs out.

    I have some broken clay pots that will fill the holes in the “regular” flower pots nicely.

    • Sharon

    This looks like a good solution to the hot, dry spells but, I’m wondering about mosquitoes breeding on the water if it doesn’t go down fast enough.

      • Tipnut

      Hi Sharon, that’s a valid concern but it’s prevented by keeping the mouth of the pot covered.

Leave a Reply

Your email address will not be published. Required fields are marked *