Keeping flower and vegetable plants well-watered is one of the most essential garden chores of summer. While most people use sprinklers, hoses, or drip irrigation to water their plants, switching to an olla pot watering system can make watering even easier, save money, and reduce water waste. If you’re interested in installing an olla system in your vegetable beds or container garden, these tips will teach you how to make and use a basic DIY olla pot for hands-off watering and healthier plants.
What Are Olla Pots?
Olla (pronounced “oy-yah”) pots are an ancient plant watering system that various cultures have utilized for thousands of years. The indigenous peoples of North and South America used vessels similar to modern olla pots for irrigation. However, olla pot-like systems were also employed in ancient Rome, Greece, North Africa, and China, and they’re becoming popular once again thanks to their ease of use.
In its most basic form, an olla pot is a porous vessel typically made of unglazed clay or terra-cotta. It is filled with water and partially buried in garden beds or planters. As a result of soil moisture tension and capillary action, water moves from the porous pot to the surrounding dry, unsaturated soil and provides moisture straight to plant roots without overwatering. Similar to self-watering planters, olla pots reduce plant watering needs and can make gardens more eco-friendly.
Benefits of Olla Pots
Compared to other plant watering systems, olla pots have a lot of perks. Like drip irrigation, olla pots water plants automatically, which makes ollas especially handy for frequent travelers and forgetful gardeners. Olla pots lose even less moisture to evaporation than drip lines, and they’re between 60% to 70% more water efficient than conventional watering systems.
Aside from reducing water waste, olla pots improve plant health by directing water straight into the soil. This encourages plants to develop deeper, sturdier roots and keeps leaves dry to help discourage foliar diseases. In addition, olla pots make it easier to irrigate xeriscapes, sandy soils, and gardens located away from other water sources. However, ollas can be used in almost any type of garden.
How to Make a DIY Olla Pot
Olla pots can be purchased online or at specialty garden centers, but you can make a simple DIY olla pot using a few basic materials.
What You’ll Need:
- Terra-cotta pot
- Plastic plant saucer
- Waterproof silicone sealant
- Flat bathtub drain stopper
- Heavy rock
1. Gather the Supplies
Any unglazed terra-cotta or clay pot can be used to make a DIY olla. However, pots between 8 and 16 inches wide work in most gardens. Smaller pots need to be refilled more often than larger pots, but they are better suited for container gardens. If needed, two large pots can be attached with silicone to make a massive olla.
After you choose a pot, select a plastic plant saucer slightly wider than the pot’s rim. The plastic lid not only slows evaporation but also prevents small animals from falling into the olla.
2. Cover the Drainage Hole
Use waterproof silicone sealant to adhere a flat bathtub drain stopper over the drainage hole in the base of the pot. Allow the silicone to dry overnight.
3. Test the Seal
Once the silicone is dry, fill the pot with water to test for leaks. Fill any leaks with additional silicone and let dry.
4. Add the Lid
Fit the plastic plant saucer over the top of the olla pot and weigh the lid down with a heavy rock so it doesn’t budge. Now you’re ready to install your olla in the garden.
How to Install Olla Pots
Whether you’re using a store-bought or DIY olla pot, install it by digging a hole slightly larger than the pot's diameter in your garden or planter. Sink the olla into the hole so that the pot’s rim is 1 to 2 inches above the soil line, and then backfill the hole with soil. Once the olla pot is in place, fill it with water and attach the lid.
The number of olla pots you need to irrigate a garden depends on the size of the growing space and the plants you’re growing. In general, olla pots irrigate a space extending outward that’s about twice as wide as the diameter of the pot, so an 8-inch olla irrigates the soil in a circle about 16 inches wide around the pot. A single olla pot is usually enough to irrigate a planter, but you may need to stagger a few ollas in larger gardens to keep plants well-watered.
After installation, continue to hand-water plants for about a month to give your plants time to grow roots and adjust to the olla watering system. Ollas usually need to be refilled once every two to five days, but this can vary. Remember to check ollas regularly to keep them from running dry.
Tips for Using Olla Pots
- While ollas work for most established plants, they are not ideal for seeds or young seedlings. Hand-water these plants until their roots are long enough to absorb water from nearby ollas. Olla pots are also not recommended for plants that crave dry soil, such as succulents and cacti.
- Ollas are particularly good for thirsty plants with fibrous root systems, like tomatoes and melons.
- To avoid disturbing plant roots, install ollas before planting.
- For best results, locate small, thirsty plants in a ring near an olla pot and move plants that like dry soil further away.
- One olla pot usually provides enough water for one large melon plant, two medium-sized tomato plants, or several small lettuce plants.
- When you use an olla pot, the top of the soil may look dry. This is OK as long as the plants look like they’re receiving enough water.
- To avoid clogs, don’t pour liquid fertilizer inside an olla pot. If ollas become clogged, scrub them with a sturdy brush and distilled water.
- Olla pots will crack in cold weather, so remove them from the garden before winter arrives. Dig up the pot, backfill the hole with compost, and put it in a dry, protected spot until spring returns.
- Drip irrigation systems with a timer can be used to automatically refill olla pots for a fully hands-off watering system.
- If desired, the olla pot saucer lid can be made into a DIY bee pool to attract pollinators. Fill the lid with clean gravel and water and wait for pollinators to stop by for a drink.