Albuquerque gets about 9 inches of rain per year. That’s less than Tucson, Arizona. City ordinances restrict the watering of lawns and gardens to 3 days per week in the summer months. That is not nearly enough to keep tomatoes and cucumbers happy and producing. Consequently, we’re always looking for ways to get water to our plants cheaply and efficiently.
When I bought our house it had sprinklers and an attempt at drip irrigation which promptly fell apart during the first spring irrigation. We’ve been watering by hand every legal day during the long growing season. Thick layers of mulch keep the moisture from evaporating in our dry heat but during high temps we need a little extra help to keep our veggies happy.
Last winter I read a book called Gardening With Less Water by David Bainbridge and was introduced to the miracle of ollas (oi-yas). Ollas are unglazed clay jars which are buried in the ground and filled with water. Since the clay is porous, the water gradually seeps out into the soil irrigating plants directly at the roots. This style of irrigation has been used all over the world from China to Mexico for thousands of years to allow increased farm yields during dry years.
So far, we have 16 ollas in our garden. I bought a fancy one (read $$$) at Plants of the Southwest and made three in my pottery class. I made a few more on the potters wheel but they are waiting patiently to be fired. Since we had a week of 100+ degree heat, I decide that our poor little garden couldn’t wait for a full kiln load to get water to their roots. We purchased a bunch of 6 and 8 inch terra cotta pots at the big box store along with some silicone caulk and tin caps that used for roofing. I put them together in about an hour and buried them in the garden this morning.
For the first couple of weeks after the ollas are installed, we still need to hand water with the hose. This gives the roots time to find their new, on demand water source
We’re in USDA zone 7b which means we’ll have the occasional freeze, with lows averaging 5-10 degrees in the winter. We will need to dig up our ollas in the winter so that they aren’t damaged. If you live somewhere like Phoenix or Southern New Mexico where you don’t really get a hard freeze, then the ollas can live in your garden year round.
Why should you bury clay pots in your garden?
- It is 50-75% more effective than surface watering, even drip irrigation, since the water is going directly to the roots of the plants..
2. After the plants are established around the ollas the soil surface isn’t getting wet. Therefore, the weed seeds – and in my case, the millions of elm seeds that end up everywhere – won’t germinate. Your days of bending over to pull the weeds is over.
3. You can’t overwater! The water moves out of the pot by means of capillary action, so if the soil is damp the water stays inside the olla. When the soil is dry, the water moves through the walls of the olla into the soil, only giving your plants what they need.
Instead of hand watering 3 days a week, we check our established ollas once or twice a week and top off the water.