How to Make an Olla Watering System at Home (and What You'll Miss)
Making your own olla watering system at home is straightforward — two unglazed terracotta pots, food-safe silicone caulk, and a cork or rubber stopper. The whole build takes about 30 minutes plus drying time. This guide walks through the build step by step, plus the honest limitations of homemade ollas compared to purpose-built ones so you can decide whether to commit to DIY long-term.
THE SHORT VERSION
01 · MATERIALS
What you need to build a DIY olla
Two unglazed terracotta planter pots, same diameter so the rims match (8–10 inches is typical for a medium DIY olla). Food-safe silicone caulk — check the label, not all silicone is food-safe and you don’t want non-food-grade chemicals leaching into your garden soil. A cork, rubber stopper, or terracotta plug to seal one of the drain holes. Sandpaper to rough up the rim surfaces for better silicone adhesion. A trowel for installation.
Avoid glazed pots — they don’t release water through the wall. Avoid pots with bottom cracks or chips, which become leak points. The terracotta should be uniform thickness as best you can tell by eye and feel. For more on clay quality, see why the clay mixture matters in homemade ollas.
02 · THE BUILD
Step-by-step DIY olla assembly
Step 1: plug the drain hole of one pot. Insert a cork or terracotta plug into the hole from the inside of the pot, then run a bead of food-safe silicone around the cork to seal completely. Let cure for at least 12 hours. Step 2: sand both pot rims lightly to roughen the surface for better silicone adhesion. Step 3: apply a thick continuous bead of food-safe silicone to one pot rim. Step 4: press the second pot rim onto the first, lining up the openings precisely. Apply firm pressure for 30 seconds. Step 5: clean any squeezed-out silicone with a damp cloth before it cures. Let the assembly dry for 24–48 hours undisturbed.
Once cured, you have a closed terracotta vessel with one open drain hole (in the top pot) serving as the fill opening. Pre-soak the assembly in water for 30 minutes before first install.
03 · INSTALLATION
Installing a DIY olla
DIY olla installation follows the same basic steps as purpose-built — dig a hole, place the olla, backfill firmly. The main difference is that the DIY olla’s fill opening is the drain hole of the top pot, which is smaller than a purpose-built olla’s neck opening. Refilling is slower (you may need a thin-spout watering can or a funnel) and the opening is harder to seal between fills. Most DIY users place a cork or stone over the opening as an improvised lid.
01 · DIY olla
$10–15 build
Two terracotta pots, silicone, cork. 30 minutes plus 24–48 hours curing. Works at a basic level.
02 · Acqua Olla
Single-piece
Specially formulated terra cotta, no seam to fail, consistent porosity. Designed in California.
03 · DIY lifespan
1–3 years
Silicone seam fails over time. Rebuild or replace every 1–3 years depending on climate.
04 · Acqua Olla lifespan
3–10 years
Tested terra cotta formula optimized for long service. Single-piece, no failure point.
For installation details that apply to both DIY and purpose-built ollas, see how to install an olla in a raised bed, pot, or garden.
04 · LIMITATIONS
What DIY ollas can’t do as well
Three honest limitations. First: the silicone seam is the weakest point and typically fails within 1–3 years from temperature swings and soil pressure. You’ll need to rebuild or replace. Second: porosity is inconsistent because generic terracotta pots vary in clay density and wall thickness — some DIY ollas release too fast, others barely at all. Third: the fill opening is small and lacks a proper lid, making refilling slower and the system less protected against debris and mosquitoes.
These limitations are real but not deal-breakers if you understand them upfront. Purpose-built ollas like Acqua Olla solve all three: single-piece construction with no seam, specially formulated terra cotta mixture tuned for consistent porosity, proper neck and lid for fast refills. For the trade-off comparison, see DIY ollas vs manufactured — honest comparison.
01 · Plug the drain hole
Insert cork or terracotta plug into one pot’s drain hole. Seal with food-safe silicone. Cure 12 hours.
02 · Sand the rims
Lightly roughen both pot rims with sandpaper to improve silicone adhesion.
03 · Apply silicone
Run a thick continuous bead of food-safe silicone around one pot rim.
04 · Join the pots
Press the second pot rim onto the first, lining up the openings precisely. Apply firm pressure for 30 seconds.
05 · Cure 24–48 hours
Let the assembly dry undisturbed. Wipe any squeezed-out silicone before it cures.
Pre-install soak
Submerge the assembled olla in water for 30 minutes before burying. Primes the clay and tests the seal.
05 · FIXES AND HACKS
Improving DIY olla performance
If you commit to DIY, three improvements help. First: choose pots with thicker walls (over 1/4 inch) for slower, more even release. Thin-walled cheap pots release too fast. Second: reseal the silicone seam annually as preventive maintenance — far easier than rebuilding after failure. Third: add a proper lid using a flat stone, terracotta saucer, or fitted cork sized to the fill opening. A good lid reduces evaporation and keeps debris out.
These improvements push DIY olla performance closer to purpose-built but don’t fully close the gap. For long-term garden infrastructure, the Acqua Olla’s specially formulated terra cotta and single-piece construction is the more reliable path.
- Use food-safe silicone only. Non-food-grade silicone can leach chemicals into your soil. Check the product label carefully.
- Match pot diameters precisely. Mismatched rim diameters create gap points in the seal. Both pots should be the same size from the same manufacturer.
- Test the seal before burying. Soak the assembled olla for 30 minutes and watch for visible water drops on the outside. Any leak indicates a failed seal.
- Plan for rebuilds. Set a calendar reminder to inspect and reseal the seam annually. Preventive maintenance extends DIY lifespan.
- Save the receipt. If the DIY approach doesn’t suit your needs, you can return materials and switch to a purpose-built Acqua Olla.
06 · WHEN TO UPGRADE
Signs it’s time to switch to purpose-built
Switch from DIY to purpose-built when you experience any of these: silicone seam leak (water drops visibly even when soil is wet), unexpected reservoir drain rates (empties too fast or barely at all), repeated cracking from freeze-thaw cycles, or simply tired of rebuilding the same olla every 2–3 years. The Acqua Olla’s 3–10 year lifespan and consistent release rate is the relief these gardeners are usually looking for.
Many gardeners follow a natural progression: build DIY to test the concept, run it for a season, then upgrade to purpose-built once they’re sold on olla irrigation. That’s a sensible path. For the full DIY vs purpose-built comparison, see DIY ollas vs manufactured — honest comparison.
Making an olla at home is a satisfying weekend project with real but manageable limitations. The build takes 30 minutes plus curing time, and the result works at a basic level for 1–3 years. For long-term garden infrastructure, the Acqua Olla’s single-piece construction and specially formulated terra cotta mixture is the more reliable path. For the full DIY vs purpose-built comparison, see DIY ollas vs manufactured — honest comparison. For why the clay mixture matters, see why the clay mixture matters in homemade ollas.
FAQ · COMMON QUESTIONS
Frequently Asked Questions
How do you make an olla watering system at home?
Take two unglazed terracotta planter pots of matching size, plug one drain hole with a cork sealed in food-safe silicone, glue the two pot rims together with food-safe silicone, let cure 24–48 hours. Bury upside-down with the open drain hole as the fill opening. Build time: 30 minutes plus curing.
What materials do I need for a DIY olla?
Two unglazed terracotta planter pots (same diameter), food-safe silicone caulk, a cork or rubber stopper for the drain hole, sandpaper, and a trowel for installation. Total cost: about $10–15.
Can I use any silicone for a DIY olla?
No — use only food-safe silicone caulk. Non-food-grade silicone may contain chemicals that leach into your garden soil. Check the product label for “food-safe” or “FDA-approved” designation.
How long does the silicone need to cure?
24–48 hours for the rim-to-rim seam. The plugged drain hole should cure for at least 12 hours before applying additional silicone. Don’t fill or bury the olla until the silicone is fully cured.
Do I need to use unglazed pots?
Yes — the whole olla mechanism depends on porous unglazed terracotta. Glazed pots don’t release water through the wall. Check the outside of the pot: unglazed terracotta has a matte, slightly rough texture; glazed pots are smooth and shiny.
How do I refill a DIY olla?
Through the open drain hole of the top pot (the assembly is buried upside-down). The opening is smaller than a purpose-built olla’s neck, so use a thin-spout watering can or a small funnel. A cork or stone over the opening between fills serves as an improvised lid.
How long will my DIY olla last?
Typically 1–3 years before the silicone seam fails. Freeze-thaw climates accelerate failure. You can extend lifespan by inspecting and resealing the seam annually as preventive maintenance.
Is a DIY olla worth the effort?
For testing the concept or low-priority plantings, yes. For long-term garden infrastructure or thirsty crops like tomatoes, a purpose-built olla like the Acqua Olla is more reliable. See DIY ollas vs manufactured — honest comparison for the honest comparison.
References
01 Bainbridge, D. A. (2001). “Buried clay pot irrigation: a little known but very efficient traditional method of irrigation.” Agricultural Water Management, 48(2), 79–88. DOI: 10.1016/S0378-3774(00)00119-0
02 Food and Agriculture Organization (FAO). “Pitcher irrigation: A simple, low-cost irrigation technique.” FAO Agricultural Technology Series. fao.org