DIY Soil Sponges

Use your kitchen and yard scraps

Photo:  Emmy Ulmschneider

By Emmy Ulmschneider, Master Gardener

I was first introduced to soil sponges at the 2018 New Mexico Master Gardener Conference and have been a fan ever since.  So, when I saw that the first July talk for the Permian Basins Master Gardeners AgriLife Extension 2024 Lunch & Learn Online Gardening Series was on soil sponges as a water saving strategy, I signed up immediately and I wasn’t disappointed.  In 2018, I learned that in New Mexico, some gardeners were making soil sponges on a large backyard, think industrial size, scale.     And in 2018, the focus was more about increasing organic matter in the soil than retaining water. 

But since 2018, we have become an increasingly arid land.  The focus in the Online Gardening Series was using soil sponges as a water retention strategy.  And as we have written previously, retaining water in the soil is a goal in our increasingly arid environment.  We need to do more than just cover our garden soil with organic matter.  Nissa Patterson, the presenter gave these key reasons for using soil sponges as they:

·        hold and store water in the ground,

·        decrease evaporation,

·        prevent water runoff,

·        decrease your water use,

·        help plants stay cool and hydrated, and

·        increase soil nutrition.    

And if you look in natural or even manmade environments, you see that there is more vigorous plant life in conditions where water collects and is naturally stored.  The organic material you are adding in a soil sponge really does function as a “wet” sponge.  All you must do is add lots of organic material to your soil, water occasionally, and keep the organic material covered.  If you garden you know that you generate organic material beyond what you might compost.

Too often, most of what you can’t use ends up in the landfill.  Creating soil sponges is a win-win situation for plants and people.   What organic materials can you use?  Basically, you can use any organic materials that you might use for composting:  gardening waste, straw, grasses without seeds, cotton or wool products, edible fruit or vegetable waste, paper, cardboard and newspaper.  Perhaps it is simpler to say, don’t use plastics or non-biodegradable materials and avoid gardening waste that has been or might have been chemically sprayed. 

So, how do we do this?  It is a simple procedure!

·        Dig a hole or trench the size you want.   The size and depth can be a small hole to accommodate the organic material left over from a nightly meal to a large trench underlying or outlining your largest garden.  Depth and area may vary with the supply of organic material you have.  Save the soil to recover the hole or trench. 

·        Fill hole with organic material.

·        Cover the hole with the soil you removed.

·        Water into the sponge.  If you want, you can incorporate a pipe to water directly into the sponge.

·        Refill or adjust the soil level by adding soil.  If the hole sinks over time as the organic material decomposes you can add more soil. 

The next time you spend time working in your garden, instead of throwing that garden waste into the dumpster, recycle it into a soil sponge.  Your garden will thank you in vegetables and flowers!

If you have questions, call the AgriLife office in Odessa at 498-4071 or in Midland at 686-4700.   Additional information, and our blog for access to past articles, is available at westtexasgardening.org.  Click on “Resources”.

Trench for soil sponge

Photo:  Emmy Ulmschneider