Marietta Daisies Garden Club

A Georgia Gardener's Guide to Using

Olla Jars in Raised Beds and Butterfly Gardens

Save Water. Grow Healthier Plants. Garden Smarter.

Georgia summers bring long stretches of heat, high humidity, and the occasional dry spell that can leave even well-established gardens thirsty. Whether you're tending a raised vegetable bed or a butterfly garden bursting with native blooms, keeping plants consistently watered can be a challenge.

One simple solution has been around for thousands of years: olla

(pronounced "oh-yah") irrigation.

What Is an Olla?

An olla is an unglazed clay pot buried in the soil with only its neck exposed above ground. Filled with water, the porous clay slowly releases moisture directly into the surrounding soil as plants need it.

Instead of watering the soil surface where much of the moisture evaporates, ollas deliver water exactly where it's needed most: at the root zone.

This ancient irrigation method has been used for more than 4,000 years in regions with hot, dry climates and is becoming increasingly popular with gardeners looking to conserve water and reduce maintenance.

Why Ollas Work So Well in Georgia

Although Georgia receives plenty of annual rainfall, our summers can swing between heavy downpours and extended periods of intense heat. Raised beds, in particular, dry out quickly because they have excellent drainage.

Ollas help by:

• Conserving water through slow underground irrigation

• Reducing evaporation during hot afternoons

• Encouraging deep, healthy root systems

• Preventing water stress between rain showers

• Keeping leaves dry, which may help reduce fungal diseases common in humid climates

• Saving time by reducing the need for daily watering

Many gardeners find they can water less often while maintaining healthier, more resilient plants.

Using Ollas in Raised Vegetable Beds

Raised beds are one of the best places to use olla irrigation.

Simply bury the olla so only the neck remains above the soil. Fill it with water and cover the opening with a lid or saucer to reduce evaporation and keep insects out.

Most vegetables thrive with consistent soil moisture, including:

• Tomatoes

• Peppers

• Cucumbers

• Squash

• Beans

• Eggplant

• Lettuce

• Herbs

Depending on the size of the olla and the weather, you may only need to refill it every three to seven days.

Spacing Tips

As a general guide:

• A 1–2 gallon olla waters a circle about 12–18 inches from the pot.

• A 3-gallon olla can water up to a 24-inch radius.

In Georgia's sandy soils, place ollas a little closer together. In heavier clay soils, water spreads farther and refill intervals may be longer.

Ollas in Butterfly Gardens

Butterfly gardens don't just feed pollinators, they also need healthy plants that can withstand summer heat.

Ollas are perfect for establishing nectar plants and native perennials while reducing water waste.

Excellent companion plants include:

• Purple Coneflower (Echinacea purpurea)

• Black-eyed Susan (Rudbeckia hirta)

• Bee Balm (Monarda)

• Blazing Star (Liatris spicata)

• Joe-Pye Weed (Eutrochium purpureum)

• Butterfly Weed (Asclepias tuberosa)

• Garden Phlox (Phlox paniculata)

• Asters and Goldenrod for late-season blooms

An olla placed near a grouping of these plants provides steady moisture while keeping surrounding soil evenly hydrated.

Perfect for New Plantings

Newly planted shrubs, trees, and perennials benefit tremendously from consistent watering during their first growing season.

Placing an olla beside a new planting helps eliminate cycles of drought stress followed by heavy watering, encouraging stronger root development and healthier growth.

Make Your Own DIY Olla

Creating an olla is inexpensive.

You'll need:

• Two matching unglazed terracotta flower pots

• Waterproof silicone or epoxy

• A cork or waterproof plug for one drainage hole

• A clay saucer or decorative lid

Seal the drainage hole in one pot, glue the two pots together rim-to-rim, allow the adhesive to cure completely, then bury the finished olla with the fill hole above the soil surface.

Maintenance Tips

• Check water levels every few days during extreme heat.

• Remove mineral deposits with a vinegar soak if the clay becomes clogged.

• Empty or remove ollas before freezing weather if they remain outdoors.

• Keep lids in place to prevent mosquito breeding and reduce evaporation.

Water-Wise Gardening for the Future

As more gardeners look for sustainable ways to conserve water, ancient techniques like olla irrigation are proving their value once again.

Whether you're growing tomatoes in raised beds, nurturing a pollinator paradise, or establishing a community garden, ollas provide an easy, low-maintenance way to keep plants healthy while using significantly less water.

Sometimes the best gardening innovations aren't new at all, they're time-tested traditions that continue to help gardens flourish, one drop at a time.