Conserving Water 2018-07-19T12:14:14+00:00

Conserving Water

The Blue Thumb Guide to Raingardens »
The Blue Thumb Guide to Raingardens »

Once you have healthy soil, the next step is to conserve and retain water in your landscape. Lots of techniques are used around the world to reduce water use and reduce water losses in gardens and landscapes.

We’ll start with mulch, drip irrigation, and garden watering tricks like ollas (buried clay irrigation pots, pictured here). We’ll then expand the discussion to landscaping considerations like terracing, swales, raingardens, and how plant choices can reduce water use.


An easy place to start conserving water in the home landscape is by mulching garden beds for both flower gardens and vegetable gardens. I typically use shredded hardwood for my flower beds and straw in our vegetable garden, but many organic materials will work – leaves, rice hulls, sawdust.

Straw Mulch

Mulch holds moisture in the soil, slows evaporation, helps keep weeds down, and adds organic matter and feeds worms as it decays. Apply a layer two to three inches thick, keep it about an inch away from plant stems, and don’t bury the plants. We have several raised beds in a community garden plot and the ones with the straw mulch (pictured) stayed moist much longer than the bed that we did not get around to mulching at first.

I do not use weed barrier fabric under my mulch because as the mulch decays into organic matter over time I want it to enrich the underlying soil, not sit on top of the fabric.

I am not a fan of rubber mulch that is made to look like fake wood chips for the same reason. It is great on playgrounds however. Some people like rock mulch but I only use it in selected locations for decorative purposes. Rock mulch gets hot in the summer sun, I find it hard to clean around, and again, I want the mulch to enrich the soil as it breaks down.

Drip Irrigation

When watering plants, drip irrigation can save lots of water compared to sprinklers by focusing water around the root zone, reducing evaporation, and limiting runoff. It is used around the world in arid areas for farming and gardening, and is well worth considering if you live in a hot or dry region.

My local hardware store carries a limited selection of drip irrigation supplies, while more extensive options are available online. Just do an Internet search for “drip irrigation supplies” and you will find plenty of options. Many also provide information to help you pick parts and assemble them.

The next photo shows a fun variation on the drip irrigation theme, courtesy of my brother Paul’s garden in Texas. He has placed rain barrels at the end of each garden bed and connected drip irrigation hoses to each. He fills the barrels with his garden hose and it only takes 5 minutes or so to fill each barrel. Then he opens the stopcock and the barrels water the garden through the drip hoses. It saves time compared to standing around watering or moving hoses.

It doesn’t take a lot of water pressure for a drip irrigation hose to work, so they work fine hooked to a rain barrel. I have found, however, that rain barrels work better with drip emitters than soaker hoses.

Drip irrigation, Paul Garden
Drip irrigation hose


Ollas are unglazed clay pots that you bury in your garden bed. Fill them with water and it slowly wicks out of the porous pot directly to the root zone of the plants. They operate like a sub-surface drip irrigation system, water deeply, and minimize water loss to evaporation. The following photo shows one being placed in our vegetable garden.

Olla in vegetable garden
Ollas, Multiple

The ollas in these photos were created by my brother Jim Dods who is a talented ceramic artist. I imposed upon him to create these as educational tools for several water conservation workshops hosted by the Olathe North High School (Kansas) Geosciences department. A flyer from the workshop is attached and explains how to install them.

There is both science and art to creating them as both the thickness of the clay and the firing temperature of the kiln affects their hardness and porosity. Several commercial olla sellers are available online. It was great fun experimenting with Jim to test different clays and kiln temperatures. If you are interested in the process, drop me a note via the Contact page.

I have also made ollas out of used soda bottles by poking small holes around the perimeter of the lower half of the bottle and then burying them up to their necks. They are not nearly as attractive as clay ollas, and they drain faster, but they are a cheap alternative and a good way to recycle waste plastic bottles. Given all the plastic trash in our roadside ditches, rivers, and oceans, I’m all for repurposing plastic bottles.
Plastic Bottle
Resilient Landscaping, Conserving Water

Ollas, Explained

Three ollas

This is an overview of ollas, explaining what they are and how to install them in your garden.
Veiw / Download Paper »


Landscape Resiliency and Climate Adaptation Toolbox, Minnesota Board of Soil and Water Resources.
Online resources to build more resilient landscapes for urban, suburban, and rural properties.

Gardening with Less Water,
by David Bainbridge

An accessible how-to book with lots of low-tech ideas to conserve water in gardens and landscapes.

Growing Food in a Hotter, Drier, Land: Lessons from Desert Farmers on Adapting to Climate Uncertainty,
by Gary Paul Nabham

Lessons from around the world on conserving water and growing food in arid areas.