Monsoon rainfall and your plants 

Contributed by Bill Redford, DLC Resources Field Manager

Typically, Arizona receives about half of our yearly rainfall totals during the monsoon season in mid-June through September. But with last year’s extreme heat and drought (frequently called our “nonsoon”) fresh in our minds, many people are wondering what this year’s summer will hold in store. And how will that affect our landscape?

Monsoon season brings, on average, 2.7 inches of rain to the valley. In 2019 and 2020, we received only 1.6 inches combined! This devastating difference, in combination with 2020’s hottest summer on record, caused many trees, palms, saguaros and plants to fail. While nature is never predictable, there are a few things to keep in mind to know how to react when we (hopefully) receive those summer rainstorms.

  1. Check your soil
    Even if we receive a lot of rain, it might not be soaking into your yard for plants to access, particularly if your yard is sloped. Test your soil’s moisture levels¬ by using a soil probe or a long screwdriver. If the screwdriver goes in at least 6 in., there is plenty of moisture for most plants and turf. Larger trees such as palms require deeper watering; ask your local nursery or hardware store for recommended amounts.
  1. Adjust your irrigation controller
    Learn to adjust your irrigation controller. Water the correct amount for your plants and schedule for nighttime watering to avoid excessive evaporation. As a general rule, for every ¼ inch of rain received, you can turn off your irrigation system for one day. A rain gauge or local weather info can help you determine how much rain was received. (Also, remember to check your soil!) Cacti shouldn’t need water unless the summer is excessively hot, and then only enough to wet down to the roots.
  1. Understand plant loss happens
    Unfortunately, it’s essential to realize that plant loss can occur if our rainfall totals are extremely low. Even in a normal year, plants and trees can fail because they are complex organisms and need a correct balance of water, sunlight and nutrients. When these elements become unbalanced, or pests or fungi attack, it may not be possible to save every plant.

How DLC responds

DLC’s Water Department regularly assesses rainfall, humidity and temperature information to alert our irrigation crews to adjust the system as needed. Our remote access controls allow us to easily change settings to account for big rainstorms.

Of course, we follow our own recommendations and frequently check soil samples to tailor water delivery to each area in a Community. Specialized irrigation techs in the field are highly trained and experienced in reviewing the effectiveness of systems. DLC is proud to combine data AND skilled field knowledge for a responsive approach to irrigation that protects the health of plants without wasting water.

Although no one has a crystal ball, we hope these tips will help your plants make it through monsoon season, whether we receive a good amount of rain or not! Learn more by visiting the DLC Learning Center.