April: Your Southwest Guide

Article excerpt

Red flag for citrus

Last year, when a citrus disease called Huanglongbing (HLB) was discovered in a tree in Hacienda Heights, California, field inspectors rushed to pull out the infected tree, cut it up, double-bag it, and remove it for further study. Then they destroyed it.

Experts say that swift action is necessary to combat HLB (also known as citrus greening), which could become a plague for the West's iconic fruit. Carried by an insect called the Asian citrus psyllid (ACP), the disease causes trees to produce bitter, misshapen, inedible fruit and eventually die; there's no known cure.

Psyllid populations, which have already killed or caused the removal of millions of trees in Florida, have been found in Southern California as well as the state's Central Valley, southwestern Arizona, and Hawaii. Although no new HLB-infected insects have been discovered, the increase in psyllid populations, particularly in Southern California, means "the chances of the disease being spread increase greatly," says Ted Batkin, president of the Citrus Research Board.

WHAT TO LOOK FOR

HLB symptom splotchy leaves

To-do list

* Plant warm-season annuals such as cockscomb (Ceiosia), cosmos, globe amaranth (Gomphrena), marigold, rose moss (Portulaca), and zinnia.

* Move containerized indoor plants, such as ficus and motherin-law's tongue (Sansevieria species), onto lightly shaded patios for a lush look.

* Plant citrus. Nurseries are filled with lemon, lime, and orange trees plus 'Buddha's Hand' citrons, 'Seedless Kishu' mandarins, and 'Cara Cara' pink navels. (See details about the Asian citrus psyllid at right.)

* Gardeners in the low deserts can grow tasty blackberries. The best selections for the low desert include 'Brazos', 'Brison', 'Rosborough', and 'Womack'.

* Plant ocotillo. For best success, buy ones that are rooted into nursery pots rather than buying bare-root plants.

* Replenish organic mulch on planting beds. To prevent evaporation of soil moisture, aim for a mulch layer of 2 to 4 inches deep. …