What Is Wrong With My Mesquite?

Are there any galls with white blisters that encircle the stem, the blisters may have burst with orange spores coming out?

Are there any oval-shaped or round holes in the bark and cracked, stained, or oozing liquid on limbs or trunks?

Are there wet, sappy areas on the bark of the main trunk, which may crack?

Do the leaves have white, cottony clusters on them?

Are the leaves and twigs covered with small, armored insects?

Western gall rust is a fungal disease that causes these symptoms. Damage is not significant on mature trees where most infections occur on branches. Infections on young trees more often result in main stem galls that can cause stem malformations and predispose the tree to breakage in high winds or under heavy snow loads. Pruning the infected branches before spore production is a good means of control.

These are common symptoms of infestation by roundheaded wood borers. Mesquite is susceptible to Mesquite girdler, Oldman longhorn, and Roundheaded mesquite borer. Prune off dead limbs during the season when adult borers are not active. Promptly remove dead or dying trees. Do not store freshly cut wood near trees. Debark or solarize logs beneath clear plastic in the sun to prevent beetles from emerging from the wood and attacking nearby hosts. Plant trees that are well adapted to the site conditions, provide proper cultural care, and protect trees from injuries.

Larvae of flatheaded borers tunnel beneath the bark, causing wet, sappy on the bark of the main trunk. Boring may kill limbs or entire trees. Prevention is the most effective management approach for flatheaded borers, which typically attack trees that have been previously injured or damaged. Providing proper care and protecting landscape plants from injury will make them less attractive to the borers. Avoid pruning spring-summer while adults are active. Properly dispose of infested wood material, as beetles may emerge from logs and attack nearby plants.

White, cottony clusters on leaves are caused by mealybugs. These tiny insects are covered with a fluffy white coating. They feed by sucking plants sap. They produce the sticky substance honeydew which makes leaves sticky. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Small, armored insects on leaves and twigs are armored scales. These tiny, shelled insects often feed on the undersides of the leaves, causing an unhealthy appearance with yellowish blotches on the upper leaf surfaces. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.

Mineral deficiencies can cause tip chlorosis or necrosis or cause foliage to discolor, fade, distort, or become spotted, sometimes in a characteristic pattern that can be recognized to identify the cause. When nutrient deficiencies occur, nitrogen and iron are the most commonly seen deficiencies. Apply only the mineral found to be deficient. Excess nutrients, on the other hand, cause symptoms like leaf tip dieback, marginal leaf chlorosis, necrosis (or burn), branch dieback, and pest problems. In this case, you should provide good drainage, and use good practices during fertilization and irrigation.