Watering in the desert can be tricky
It is essential to know when to water, how often, and even more important, how deep to water. These factors are crucial for the success of any landscape type. Here we will discuss these topics and help ensure adequate irrigation throughout the hottest months in the Phoenix area.
The best time of the day to water your trees and plants is in the early morning. The ideal time to turn your drip system on and give your plants a good drink for the day is between 4 am and 6 am. As temperatures rise in the summertime, the trees and plants in your yard will need to maintain adequate moisture to ensure proper growth and root establishment. It also helps to prevent any wilting, burning, or stress associated with higher summertime temperatures.
Stay away from watering during mid-day, evening, or night time. Midday irrigations are often too late and can cause thirsty trees to stress more. Watering in the evening time, especially during moist or humid nights will promote mold and fungal growth that can affect your plant or your trees overall health.
Now that we know the right time of day to water, it’s necessary to understand how deep, and how often, to water. Most new trees or plants will benefit from being watered every day for the first week.
For ground covers or smaller shrubs, ensure that your water is getting into the soil at least 12 inches deep.
For medium-to-large shrubs, your water should reach 12 to 18 inches deep.
For trees, the water should reach 2 to 3 feet deep.
To check the depth of the water and make sure it drenches the soil, you can use a piece of rebar, a dowel rod, or one of the two-foot planting flags that we have here at the nursery. You will want to probe the soil and several different areas around the initial planting area and ensure that the water is getting to the depths recommended.
If you are probing the soil and the rods only going down one foot into the ground, probe other areas, and if you’re still reaching a depth of one foot, then you know you are not watering long enough. You can now adjust your system to run longer and then probe again to ensure the proper depth.
Tropical varieties should be watered in the summertime when the temperatures above 100° 4 to 5 times a week.
Subtropical varieties should be watered 3 to 4 times a week.
Desert varieties can be watered about two times a week or every third or fourth day.
Making sure that the water is getting down 2 to 3 feet on the trees and saturating the entire root ball is important and will eliminate how often you need to run your system if you’re watering to the proper depth. You can also check the top of the soil. When the soil is dry to the extent of an inch or two, it’s typically time to water again.
Lastly, you should water at the drip line (the canopies edge or tips of the canopy), which is where the feeder roots exist. As the tree or plant establishes, move the drip lines to the side of the canopy. This will ensure that your roots continue to grow in the right direction.