What Is Wrong With My Tamarisk?

Are the leaves dry and brown, small beetles can be found?

Are the plants yellow and stunted, roots have swollen galls?

Does the plant begins to wilt and are there zigzag paths in roots or stems?

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

The tamarisk beetle (Diorhabda spp.) is the biological control strategy for managing tamarisk, as this plant species is considered invasive. The tamarisk beetle and its larvae feed on the leaves of tamarisk, leaving them dry and brown and, in doing so, significantly weakens the plant so that mechanical and chemical controls are more effective. This is referred to as “defoliation” or “browning”. If you're growing tamarisk in your landscape, the beetles may have migrated from nearby sites where the biological control of tamarisk had been deployed.

Yellow, stunted plants and roots that have swollen galls indicate root-knot nematodes. Other symptoms are plants wilting during bright, hot days. Prevent root-knot nematodes by applying chitin or introducing parasitic nematodes to the soil before planting. Solarizing the soil also helps in preventing root-knot nematodes.

These symptoms are caused by Black vine weevil larvae. The larvae are small whitish grubs, which feed within the fruit, stem, or roots of plants. The larvae feed on the roots and stems. The feeding can girdle the stem, killing the plant. Drench the soil around your artemisia with the predatory nematode solution. If there are adult weevils, knock them from the plant on a piece of cloth and destroy them.

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.