Just Because Its a Cactus Doesn't Mean it Loves it in the Mojave!

            

Some pictures of "torch" cacti in the yard of one of my readers. Great job!

Several questions were sent to me regarding cacti. In general, the most common reason for failure of cactus is watering too often. The second most common reason for cactus problems is because it was put in a hot, bright location when it should be located in a protected part of the yard. The third reason is because the cactus was damaged during our winter cold temperatures and prefers being planted in a warmer climate.

Argentine Giant Cactus (Not yet!)

Automatic Irrigation

            Be careful when putting cacti on an automatic water or irrigation timer. They are watered so infrequently that it sometimes makes sense to water these plants manually with a hose rather than automate it. When cacti begin to shrivel, it’s time to water. When they look plump and firm, they don’t need water.

            If you’ve got lots of cacti and you are using an automatic timer, then run that station or valve when they need water but make sure they have good drainage if you water them automatically (without looking at them). A hose, manual timer and sprinkler also makes sense for larger desert plants.

Watch for winter low temperature damage. Know your cactus!

Water Cacti 12 inches deep

            Medium-sized and small cacti should be watered about 12 inches deep. Large desert plants like a saguaro or Joshua tree should be watered 18 inches deep and have water applied to an area underneath them equal to at least half of their height. Watering a large area under large plants helps keep them stable and keeps them from falling over when the tops get large and heavy. Watering any of these plants too often can cause disease or unsightly growth problems.

Cactus from the Sonoran Desert, like this nopal, may require warmer temperatures when planted in the Mojave.

Your Cactus Has a Name

            Find out the scientific name for your cactus and Google it. Learn where it originated from. Some cacti are native to the southeastern US or higher elevations in other countries. In these locations it was cooler so they will need protection from late afternoon sun in the Mojave Desert. Cacti native to our Southwestern deserts do not. They can handle hot and dry locations. Learn if your cactus should be planted in a gentler landscape location or can handle the harsh ones.

Watering only at the base of most cacti results in blowover with wind and if they get tall like this one in Parker, AZ.

Know Where it Comes From

            Some cacti are tropical or subtropical and get damaged because of our low winter temperatures in the Mojave Desert. Cacti which can handle low temperatures of 20° F or lower probably will not need much winter protection in all but the coldest years. Other cacti which are less tolerant of these low temperatures might, depending on your landscape microclimate and location in the valley.