Cheap DIY Ollas for Deep Watering Summer Beds

July in Redmond hits different than the rest of the year. Six weeks of grey drizzle, then suddenly it’s 92 degrees and your tomatoes are drooping by 2pm and you’re out there with a hose feeling like a bad plant parent. I’ve been that person. Many times. Cheap DIY ollas fixed that for me, and I’m going to show you how to build them.

That’s what got me into ollas. Ancient irrigation tech, dirt cheap to build, and honestly kind of satisfying in a nerdy buried-pot sort of way. If you’re already dialing in what to grow this month, now is the right time to get these in the ground before the heat really arrives.

What You’re Actually Building

Two unglazed terracotta pots, glued rim-to-rim, buried in your bed with just the neck sticking out. You fill them with water, cap them, and the porous clay weeps moisture slowly into the root zone. Plants drink what they need. You refill every few days instead of watering daily. That’s the whole thing.

No electricity. No timers. No drip tape that gets chewed by something. Just physics. I love it when cheap and effective turn out to be the same thing.

What You Need

• Two unglazed terracotta pots, same size (4-inch or 6-inch work well for most beds)
• Food-safe silicone sealant
• A cork or small stone to plug one drainage hole
• Something flat to use as a cap (a terracotta saucer, a flat rock, a piece of slate)

Total cost per olla: somewhere between $4 and $7 depending on pot size and where you find them. Garden centers, big box stores, the end-of-season clearance bins at hardware stores. All fair game. I found a stack of 4-inch pots at a thrift store once for almost nothing and I was, not to put too fine a point on it, extremely pleased with myself.

How to Build One

Plug the drainage hole in the bottom pot first. A wine cork works. A pebble with a dab of silicone works. A small flat rock works. You just don’t want water pouring straight out the bottom before it has a chance to do anything useful.

Then run a bead of food-safe silicone around the rim of one pot and press the second pot rim-to-rim against it. Hold it, prop it, let it cure for at least 24 hours. The seal doesn’t need to be perfect, but it should be mostly there or you’ll just have a weird inefficient funnel underground.

I got impatient the first time and tried to bury mine after a few hours. The pots slid apart in the hole. Learned that one the hard way, as I learn most things.

Burying It

Dig your hole, drop the olla in bottom-first, and backfill until the neck (the narrower top opening) is just above soil level. You want about an inch of clearance so you can see it and fill it without getting a handful of dirt every time.

For a 4-inch olla, you’re covering roughly 1 to 2 square feet of root zone. A 6-inch pot gets you closer to 3 to 4 square feet. So for a standard 4×8 bed with tomatoes, peppers, and squash, you’re probably looking at 3 to 4 ollas depending on spacing.

How Often to Refill in Zone 8b July Heat

In a Redmond July, with temps regularly hitting the mid to upper 80s and some weeks pushing into the 90s, I’ve been refilling my 6-inch ollas every 2 to 3 days. Smaller 4-inch pots need refilling closer to every day or two in peak heat. It sounds like a lot but it’s way faster than hand-watering a whole bed, and the plants genuinely look better for it.

Midsummer is also when I think about other ways to keep the beds from baking, like a piece of cheap shade cloth over the most sensitive stuff. Ollas handle the roots, shade cloth handles the canopy. Belt and suspenders gardening.

Which Crops Actually Love These

Tomatoes, squash, and peppers are the big three. All of them are thirsty, all of them hate inconsistent moisture (blossom end rot is basically what happens when a tomato gets stressed about water, which, relatable), and all of them have deep enough roots to actually benefit from water delivered below the surface.

Cucumbers do well too. I wouldn’t bother with lettuce or radishes. Shallow-rooted, and they bolt before the olla setup even pays off. Save the ollas for the crops you’ve been nursing since March.

One More Thing

Cap your ollas. A terracotta saucer sitting on top keeps mosquitoes out and slows evaporation from the opening. I use a flat rock because I have a lot of flat rocks and zero shame about it.

Come August you’ll be in full harvest mode and grateful you’re not running a hose twice a day. If you’re planning ahead for what that looks like, there’s a good rundown on the August garden rhythm worth reading now while you still have time to set things up right.

You could spend a lot on drip irrigation. Or you could spend seven dollars and bury some pots. I yam what I yam.

Photo by Naoki Suzuki on Unsplash