So even though I've talked about this topic quite a bit over the past couple of years, I think it's time for me to start from square one and really try to cover the topic from top to bottom. For those of you who are new, I recommend reading on, because ollas are awesome. For those of you who already know about ollas, I recommend reading anyway. Maybe you'll pick up some new tips. :)
What is an Olla Anyway?
Let's start with the basics: what are ollas? Ollas are unglazed pots that you can use for irrigation. They come in all shapes and sizes, but the ones I use look like this:
The concept behind ollas is simple: You bury the ollas in the ground with the neck sticking out above the soil line, bury your plants around the ollas, and then fill the ollas with water. When you're done, your garden might look something like this:
The water inside the ollas will slowly seep out through the ceramic walls of the pots, giving the plants exactly as much water as they need--not too much, not too little. In other words, ollas are the Baby Bear of watering techniques: just right. All you have to do is keep the ollas full of water and your plants will take what they need.
Will My Plants Grow As Well with Ollas?
- The ollas deliver just the right amount of water--not too much, not too little.
- The clay in the pots actually delivers a few extra "bonus" minerals to the plants.
- If you happen to use rain water in the ollas (like I do), the water is purer than the water delivered via a standard drip irrigation system. (This might not be true in your area, but here in Gilbert, the municipal water is a little salty.)
Are There Any Tricks to Starting Seeds with Ollas?
Hand-water any seeds that you plant around ollas until they sprout. (Seeds can't really take advantage of the damp soil until they actually develop roots.)
How Often Do You Need to Fill the Ollas?
The interval between refills varies a lot. I've gone anywhere from every two days in the summer to once a week in the winter. Other factors can impact how often you need to refill your ollas too. For instance, I try to keep them topped up for seedlings, since their roots won't be long enough to reach the bottom of levels of the ollas. Non-intuitively, I also sometimes find that ollas need to be refilled less often when plants get very mature. This is because the plants' roots have adhered so completely around the ollas, no water is getting lost in the soil--it all goes straight to the roots.
Honestly, this is one of the biggest downsides of ollas--constantly refilling them. If you're busy, traveling, or just kind of lazy (all of which apply to me at times), refilling ollas on such a regular basis can be a real drag. Happily, David Bainbridge's new book, Gardening with Less Water gave me a great idea for how to fix that--create a system where the ollas fill themselves. My husband and I just finished putting together a system where we're feeding water into the ollas using tubes attached to rain tanks. (But that's another post.)
How Much Do Ollas Cost?
In my neck of the woods, a two gallon olla costs about $34. I think most people would consider that pretty pricey. (Of course, if you compare that to installing a drip system attached to a controller, it's cheap, but I don't think that's what most people are comparing it to.) Personally, I think it's worth it, but I know most people aren't willing to shell out that type of cash.
- When I've done a side-by-side test of a DIY olla vs. the real thing, my plants did better with the real thing. I'm not 100% sure why, but I have a good guess: my test was conducted in hard conditions--it was an Arizona summer and I was growing the plants in (amended) native soil (i.e., clay). The DIY olla was probably at least slightly less porous than the real thing, and just could not deliver water as well. As a result, the plants getting water from the DIY olla suffered.
- Having said that, I've learned since that's there are ways to test for porosity in unglazed pots. Just spray them with water and make sure that they immediately get wet. Or dunk them in water and make sure they get uniformly wet. If there are any dry spots, it's not suitable for an olla.
- Another thing I've learned since writing my original blog about creating your own ollas is that it's totally not necessary to glue to ollas together (like most tutorials recommend). Instead, just find a cork, plug the bottom of a pot, and use that as an olla. Place a saucer on top for the opening. It makes it a whole heckuva lot easier to get the water in!
Do Ollas Require Maintenance?