You may or may not be familiar with ollas, but they’re making a comeback, especially with the continuing ‘severe’ drought in the western US states. People are catching on to the fact that they can maintain a planter or a small garden plot, using a lot less water than overhead watering or drip irrigation, even in arid states. Nicole ran into one such person recently, Laura, who was generous enough to send Nicole some great information and photos documenting her ongoing gardening experiences with ollas.
In addition to their water conservation abilities, another benefit to using ollas or clay pot irrigation, is that surface soil stays dry so there are less weeds. So, what exactly is an Olla (pronounced “oy-yah”) ? Here is the definition from DrippingSpringsOllas:
An OLLA is an unglazed clay pot fired at a low temperature. This allows the pot to remain porous. The OLLA is buried in the ground with neck exposed and periodically filled with water. The water seeps into the soil at a rate that provides adjacent plants with a constant water source at the roots.
Here’s what Laura says about using ollas in her garden:“I have homemade ollas, which can be made fairly cheap and are pretty useful (they are created by gluing together two terra cotta pots with food grade silicone, plugging the bottom hole with a cork and covering the top hole with a small, glazed saucer) and commercially made ones which are good because they have more volume so you don’t have to fill them as often. Ollas can save around 50 to 75% of the water that traditional watering uses, depending on what plants you have. Don’t use them around woody rooted plants as those roots can grow around the olla and eventually break it.
Your ollas can be reused every year. If you have mineral build up after using them (depends on your water), you can clean them out once a year with a diluted 1:1 vinegar and water solution. What makes themso efficient is that there’s no water evaporation or water going below the root zones. Each olla is fitted with a lid to prevent evaporation, and the lid has and added benefit – it prohibits mosquito breeding. Plus you’ll find you have way fewer weeds since the surface soil is dry, meaning you save time by not having to weed very much. I hardly had any weeds.
I’m still experimenting on how far in a circle I can plant, but it’s usually about twice the diameter of the olla.” Thanks again Laura for this info.
How to Use an Olla in Your Garden
1. Bury the olla in the soil of the garden bed or planter leaving the top slightly protruding (enough so it can be seen and soil won’t spill into the opening when refilling). Ideally the neck of the olla is glazed to prevent evaporation – but you can also cover it with mulch.
2. Fill the olla with water and cap the opening. If you purchased a commercially made olla, it will come with a cap. If you are making your own, a clay plate, saucer, rock or another choice, whatever will prevent evaporation, soil intrusion and mosquito breeding is good.
3. Refill once to three times a week, depending on the soil, climate, time of year and plant needs. It’s best to keep the olla at no less than 50% full to prevent the build up of salts and minerals.
4. Spacing – per drippingspringsollas.com – once again it “depends on plant selection, soil type and temperature. But as a general rule, plant within 18 inches from center of OLLA or 12 inches from the outer wall”.
Benefits to Irrigating with Ollas
- You can reduce watering needs in your garden by 50 to 75%
- They water the roots instead of the surface of your garden or raised bed preventing soil compaction
- Reduce weed growth as soil surface remains dry
- Roots grow deeper and you don’t have to water as often
- No water is lost to evaporation or runoff
Note: ollas may not be a good fit for your garden if you’re not around to refill them as needed.
Where to Buy Ollas
Dripping Springs Ollas have a 2 gallon size available on Amazon (see lead photo). The bigger sized olla means you won’t have to worry about refilling them as often. They are a slight investment up front, but in the long run you are saving a ton on your water bill by using one of the most efficient forms of irrigation.
If you have a planter that needs watering, a slightly less expensive option is the Plant Nanny. You dig the Plant Nanny into your planter, fill and empty bottle of wine with water and turn it upside down into the plant nanny. “Each ceramic Plant Nanny Stake is specially designed to release just the right amount of moisture into the soil. You create the water reservoir by filling an empty wine, water or soda bottle with water and attaching the included, drip-free, threaded adaptor. As the soil begins to dry, the device slowly releases more water (through gravity/diffusion).”