Water-saving strategies in the landscape

It’s June, days are getting longer and the temperature is heating up.

According the U.S. Drought Monitor, the entire state of New Mexico is currently under severe to exceptional drought conditions. How can we keep the rain that may fall on our properties and use it to the best advantage in drought conditions?

There are two strategies that you can use to do this at little cost, low-sweat equity, and no construction needed. Did you know that moisture in the soil accounts for more fresh water storage than all the rivers, swamps and marshes in the world combined?

Our first strategy to slow down and keep water on the landscape is by improving the soils’ ability to hold water. How do we do that? We add organic matter (OM) to our soils. Desert soils are notoriously low in organic matter. With sparse vegetation and slow decomposition due to the lack of precipitation, our soils naturally have little organic matter.

Adding organic matter to soils increases the ability of the soil to hold water and nearly all of that water is available for use by plants. OM has the ability to absorb and hold up to 90 percent of its weight in water.  Clay soils can hold more water than sandy soils, but that water is held so tightly to the clay particles most of it is unavailable to plants even though it remains in the soil for a longer amount of time (NRCS).

Adding organic matter to sandy and clayey soils is the answer for improved soil health and water retention. Based on countless soil tests I have reviewed over the past seven years, you’ll be lucky to have .02 percent organic matter in your native soil.

Recommended amounts of organic matter for good plant growth in a lawn is 2 to 3 percent and for ornamentals and vegetables 4 to 6 percent.

How do you get there? By adding compost and organic matter to your soil at the beginning of each growing season. This is easy for open areas but what about existing landscape beds? Fortunately, you don’t need to till your beds or dig them up, simply add a 2 to 4-inch layer of compost to the surface of the bed. You can gently rake it in or simply allow nature to take its course.

Over time and with watering, the compost will begin to decompose and make its way down into the soil profile.

The second way to keep water on your property and decrease loss through evaporation is by applying a 2 to 4-inch layer of mulch to the top of your soil. Mulch is defined as any material, natural or other applied to the soil surface, but not tilled or mixed into the soil below it.

Common organic mulches include tree chips, pecan shells, pine needles, straw, leaves, grass clippings, and other plant residues as well as inorganic mulches such as rocks, sand, stone, weed control fabric, and plastic. This can be placed on the soil surface after you’ve laid down your compost.

With our intense sunlight and high summer temperatures, bare soil surfaces can easily reach 120 degrees. Mulches moderate the soil temperature keeping it cooler in summer and warmer in the winter.  Mulching provides many benefits to your soil and plants. It increases the ability of water to penetrate the soil surface and the soils’ ability to hold that water. It decreases salt build-up in the plant root zone, suppresses the growth of weeds which compete for soil water and nutrients, decreases soilborne diseases, and organic mulches provide a slow release of nutrients as they decompose.

Organic mulches also promote tree growth especially in young trees. (Downer and Faber).

Another strategy for dealing with drought is planting drought tolerant native and naturalized ornamental plants in your landscape.  The Nature Conservancy has released a list of Climate Ready Trees for the Albuquerque area.

For more information  visit nature.org/content/dam/tnc/nature/en/documents/Climate-Ready-Trees-Location-Lists-Nov2020.pdf

For Soil organic matter and mulches visit aces.nmsu.edu/pubs/_circulars/CR687/welcome.html (NMSU Circular 687 – Managing Organic Matter in Farm and Garden Soils), anrcatalog.ucanr.edu/pdf/8672.pdf (Mulches for Landscapes), and aces.nmsu.edu/ces/yard/archives/052221.html (Southwest Yard and Garden archives June 2021).

Want more gardening information, visit the NMSU Publication site at extension.nmsu.edu.

Free virtual classes are offered from 3-4 p.m. on the first and third Wednesday of the month with Ready, Set, GROW! On the second and forth Wednesday through Gardening with the Masters.

For upcoming classes and recordings visit aces.nmsu.edu/desertblooms/ready-set-grow.html and http://sandovalmastergardeners.org/gardening-classes/gardening-with-the-masters-online/ Classes are free, registration required.

(Lynda Garvin is the interim county program director and agriculture agent/extension Master Gardener coordinator for the Valencia County Cooperative Extension Service.)