The secret farmers bury underground to stop watering their gardens all summer

The Problem

The secret farmers bury underground to stop watering their gardens all summer

The “secret” is usually buried clay pot irrigation, often called an olla. An olla is an unglazed terracotta pot buried in the garden with only the neck or lid above the soil. You fill it with water, cover the opening, and the porous clay slowly releases moisture underground as the soil dries.

To effectively implement this system, start by selecting the right size olla for your garden. A standard olla is typically about 1 to 2 gallons in capacity. For a small garden or a few plants, a smaller olla will suffice, while larger gardens may require several bigger ollas. It’s crucial to space them appropriately; generally, placing them about 12 to 18 inches apart allows adequate coverage for your plants' root zones.

This does not mean you never water all summer. It means you water the pot instead of soaking the whole garden bed. In hot weather, you may refill it every few days; in mild weather or mulched soil, it can last longer. Monitoring soil moisture is essential, especially for beginners. A simple soil moisture meter can help you determine when the soil around the olla is drying out.

The big advantage of this method is efficiency. Water goes directly to the root zone instead of evaporating from the surface. This can reduce wasted water, keep leaves dry, and help plants handle heat better. To further enhance this system, consider applying a thick layer of mulch (3 to 4 inches) over the garden bed. This not only retains moisture but also suppresses weeds, which can compete for water and nutrients.

How to use it: bury an unglazed clay pot near tomatoes, peppers, cucumbers, squash, herbs, or flowers. Leave the opening above soil level, fill it with water, then cover it with a rock, saucer, or lid to block mosquitoes and debris. Make sure to check the olla regularly for cracks or damage, as this can affect its ability to retain water.

Space ollas close to the plants. A small pot only waters a small area, while a larger clay vessel can support a wider root zone. Heavy mulch over the bed makes the system work much better. For example, if you have a raised bed of tomatoes, consider placing one olla for every two to three plants, ensuring that each plant has access to the water being released.

Best for raised beds, vegetable gardens, dry climates, sandy soil, containers, tomatoes, peppers, herbs, and gardeners who want less daily watering. However, it’s important to note the limitations of this method. It is not suitable for seed starting, very shallow-rooted crops, waterlogged clay soil, plants far from the pot, or gardens where you need broad sprinkler-style coverage.

Beginner mistakes often include burying the olla too deep—only the neck should be above ground. This can hinder the water's release. Also, avoid placing the olla too far from the plants, as roots may not reach it, resulting in inadequate watering. Regularly check the water level by simply removing the lid; if it’s empty, refill it immediately.

The real trick is not magic. It is slow underground irrigation plus mulch. Together, they keep moisture where roots can use it and reduce how often you need to drag out the hose. With practice, this method can lead to a thriving garden with significantly less water usage throughout the summer months.

The Result