Common mistakes that harm rather than help your landscape during the summer

Are you looking for ways to help your trees and plants thrive under the intense heat of the desert summer sun? Desert-adapted plants are naturally suited for this climate, but they do require some additional care during the summer months to truly flourish. Many enthusiasts unknowingly make changes that can be detrimental to their trees and plants. 

Here are five typical mistakes to steer clear of this summer to keep a healthy and vibrant landscape.

Running the irrigation system for short durations throughout the day. This seems like a great way to keep your trees, shrubs, and groundcover happy, but it can do more harm than good. That water evaporates and never reaches the roots. When summer temperatures are peaking and humidity is low, your landscape needs a deep watering once a week. This allows the water to sink deeper into the ground, where the clay soil is built to hold water as a reservoir for desert plants. Use the “cycle and soak” method to prevent this waste and provide your plants and grass with even watering. Break up the watering into a stop-and-go cycle. For example, run your irrigation system just to the point of runoff, then shut it off for 30–60 minutes and water again. This allows the water to seep into the ground.

Adjusting your irrigation system only twice a year. Landscape watering requires more frequent adjustments than you may expect. Gradually altering your watering times, preferably on a monthly basis, can conserve water and reduce your water bill by up to 30 percent. That’s why some cities offer rebates for new smart irrigation controllers that adjust watering cycles based on weather conditions and soil moisture levels. To further assist you in changing your irrigation properly, text WHENTOWATER to 1-844-416-1428 and receive a text message on the first of each month with a link to that month’s unique watering guide . This guide reminds you to change your settings as the weather changes and gives precise watering instructions for all your plants.

Thinning trees. For some homeowners, “thinning” a tree involves cutting away the smaller inner branches while keeping the growth at the tips of the longer branches. This approach is flawed for several reasons. Firstly, it exposes the inner branches to potential sun damage. Secondly, it eliminates leaves, which serve as the tree’s energy source, thus diminishing its ability to fend off pests and diseases. Thirdly, this method concentrates all the weight at the tips of the branches, known as “lion tail pruning,” making them more susceptible to breaking in strong monsoon winds. It's recommended to prune just before growth begins in spring. If pruning is necessary, limit the cuts to the outer 20 percent of the tree canopy and never remove more than 25 percent of the living leaves, stems, or branches each year.

Shearing, shaping, and over-pruning shrubs. It’s not wise to shear desert-adapted shrubs. Removing all their natural foliage forces these plants to develop a shell of leaves that struggles to produce the sugars they need for growth. Over time, you'll notice that the shrub becomes woody inside due to a lack of sunlight, leading to the formation of woody holes from stress, which can ultimately result in the shrub's death. Foliage serves as a protective shield, helping a tree or shrub shade its inner core and roots from the intense sun. It’s best to leave your plants and trees untouched during the summer and to prune them lightly and minimally when the weather is cooler. Additionally, remember to choose the right plant for the right space. Before planting a shrub or tree, ensure it has adequate room to grow and spread, which can help reduce the need for heavy pruning later on.

Failing to check your irrigation system regularly. When it’s hot out there, it’s easy to leave the watering duties to your irrigation controller. Additionally, it’s typical for irrigation systems to run during the night because it’s a good idea to water when temperatures decrease after sunset. Still, there’s no one around to spot a broken emitter or water bubbling up from the ground due to a broken line. A broken sprinkler head can waste up to 7 gallons of drinking water per minute. A leak also means that somewhere in your landscape, plants or trees are not getting enough water to survive. Take a walk around your yard periodically to check for signs of leaks. Watch your water bill for sudden increases in usage. These spikes could indicate a leak. It’s worth your while to turn on your irrigation system monthly and walk your property to look for leaks. Ask your landscaper to manually turn on your irrigation system and alert you to any leaks. AMWUA’s Smart Home Water Guide  is a straightforward, step-by-step guide that helps you locate and repair leaks. Many cities also offer free irrigation classes to help you.

Here’s a bonus tip: In summer, the sun rises farther north than in winter. This means plants that usually grow well in shade during winter may struggle with the afternoon sun in summer. Move your potted plants to shadier spots in your yard or on your porch. To help these plants, consider planting hardy, fast-growing trees like Palo Verdes or installing shade solutions, such as a shade sail. If you are designing or redesigning your landscape, remember how the sun's position changes with the seasons. This can help you choose the right trees, shrubs, and plants for each area of your yard. AMWUA’s landscape pages can guide you in selecting and caring for your plants with the right amount of water while keeping your space beautiful.

For 56 years, the Arizona Municipal Water Users Association has worked to protect our member cities' ability to provide assured, safe, and sustainable water supplies to their communities. For more water information, visit www.amwua.org .