If you are like many of the residents at Sun Lakes, you’re not a native of Arizona and may not have a green thumb either. However, you probably have some Citrus and Palms on your property. I do and I probably should have cactus or plastic plants to care for. In the northeast, Mother Nature does a good job in taking care of much of the landscapes’ requirements. Arizona is very different and replacing trees is going to be expensive.
I thought I would share some of my lessons on how not to kill your Citrus and Palms.
First, I learned that I could not rely on my landscaper to know anything about the care of trees; pruning and cleanup seems to be their expertise. Next, I learned about the irrigation system that came with my house. It’s one of those systems that require a Ph.D to operate. When the landscape started dying, I got smart and read the manual. I set the water on a schedule, and though I was finished. The plants did well for a while but you have to give them what they need if you want to keep them alive.
Citrus and Palms have similar watering requirements. Mature plants need to be watered very well and then the soil needs to dry out a bit so that the roots can get oxygen. In the winter or warm months, trees should be watered so that the ground around the tree (diameter of the tree’s canopy) is saturated with standing water for an hour. Watering about 1x every 14-21 days is a good rule of thumb. Soil type (drainage) and other factors effect exactly how much you should water. When the weather changes from pleasant to very warm (late spring & early fall), increase the watering cycle to 1x every 14 days. When it gets hot (100+ degrees) increase the watering cycle to 1x every 10 days.
Too much water will deprive the roots of oxygen, resulting in yellowing and leaf loss. Too little water will result in leaf shrivel and retarded growth. Both conditions create stress that over time can make your tree susceptible to other disease if not outright killing it.
Don’t water the leaves. Water from a hose or sprinkler can cause two problems. Droplets can focus and magnify the sun’s rays, resulting in sun burn. Arizona water is very salty and citrus leaves are stressed by salt. Too much salt will cause leave loss.
Irrigation heads should be about three feet away from the trunk. You want to water the roots, not the trunk. Mature trees should flare out where the trunk meets the ground and Citrus should show the top of the root attachment to the trunk. If the trunk is the same diameter at the ground as it is a foot above, the tree is too deep and raking away several inches of earth / mulch will help.
Trees are sensitive to the environment and pruning should be done in February before new growth buds appear. Citrus trunks should be painted with citrus paint if they are exposed to the direct sun, especially if there are any signs of blistering.
Fertilize 3x a year – Valentine’s Day, Memorial Day and Labor Day. I use Citrus Grow and Palm Food. Both are at the local hardware store and nursery.
Palms trees also have a need for Magnesium (Mn). When Palms start to yellow, this may be an indication that the manganese in the soil is depleted. Epsom Salts are cheap and full of manganese; there are Palm application instructions on the label of the larger packages.
I wish someone had told me all this when I moved here a few years ago. Tree removal and replacement can cost several thousand dollars.