Signs of Sick Shrubs in Fort Worth, Texas

Shrubs fail from the roots up, and usually from water

Foundation plantings live in the hardest microclimate on a property: reflected heat off brick, compacted builder's fill, a drip line that concentrates roof runoff on one spot, and irrigation zoned for turf rather than woody plants. Most shrub problems in Fort Worth trace back to water — too much, too little, or too shallow — before they trace back to a pathogen.

By symptom

Sudden browning of a whole branch or one side

Usually root damage or a vascular blockage on that side. Check for a buried stem base, a girdling root, or trenching work done nearby in the last two years.

Leaves yellow between green veins

Iron chlorosis, and in Fort Worth's alkaline soil it is endemic. Hollies, gardenias, azaleas and nandina show it readily. Chelated iron corrects the symptom; species choice avoids it permanently.

Boxwood thinning from the inside out, with black streaking on stems

Possible boxwood blight, which is serious and highly transmissible on tools and clothing. Do not shear it and move to the next plant. Get it identified first.

Photinia with red-bordered grey spots on the leaves

Entomosporium leaf spot. It is effectively endemic to red-tip photinia in North Texas, it defoliates the plant repeatedly, and it eventually kills it. Photinia is a poor bet here; most people are better served replacing it than treating it annually forever.

Wilting despite wet soil

Root rot — Phytophthora, most likely. The soil is holding water the roots cannot live in. Fix drainage first; fungicide without drainage correction is money spent on a symptom.

White cottony masses, sticky leaves, black film

Scale or mealybug, with sooty mould growing on the honeydew. Treatable, and usually a sign the plant is already stressed by something else.

Three fixes that solve most of it

1. Check planting depth. The stem base should flare where it meets the soil. If it goes into the ground like a broom handle, it is too deep.
2. Mulch properly. Two to three inches, pulled back from the stems. Not the volcano of mulch piled against the trunk that landscapers favour.
3. Water deeply and less often. Turf irrigation schedules keep shrub roots shallow and shrub crowns wet — both bad.

If several shrubs are declining together, the cause is nearly always the site rather than a disease moving between them. Our Fort Worth assessment covers shrubs as well as trees, and it is free.