Botanic Garden >> Gardening > >> Question and Answer >> Plant Species >> Trees

Scale Insects and Sooty Mold on Linden Trees

Condo association linden (19-20 yrs) shows dark mold on leaves and blackened sidewalk below. Other lindens unaffected. Landscapers proposed Sevin.

Diagnosis: Scale Insects

Scales live under protective shells, suck sap, secrete honeydew → sooty mold grows on honeydew. Sevin (contact insecticide) won't penetrate shells.

Effective Treatment

Bayer Advanced Tree & Shrub Insect Control (soil drench): Systemic action kills scales as they feed. Takes weeks but lasts season. Orthene spray may work during brief crawler stage but timing is difficult.

For large trees, soil application is only practical method. Control scales → sooty mold disappears.

Trees: Black Sooty Mold on Hackberry: Controlling the Aphids and Scale Behind It; Hydrangea Tree Yellowing and Leaf Drop: Water Stress, Not Spray Damage; Dwarf Grapefruit in Greenhouse: Leaf Yellowing and Browning; Lemon Tree Mysterious Decline: No Clear Pathogen, Focus on Cultural Care; Carrotwood Pale Curled Leaves After Pruning: Stress or Pests?; Linden Tree Care: Gall Mites, Leaf Issues, and Treatment Options; Pruning Young Empress Trees: Managing Suckers for Strong Structure; Identifying Green Growths on Littleleaf Linden Leaves; Tree Leaf Identification Resources for Science Projects and Homeowners; Identifying a Non-Blooming Magnolia as Possibly Fraser Magnolia

Garden Articles

Plumeria Spider Mites: Organic Control and Plant Health

Ginkgo Leaf Curl After Wet Spring: Temporary Stress Response

Mango Tree One-Sided Dieback: Prune to Healthy Wood

Ginkgo Tree with Small Leaves and Suckers: Cold Injury and Stress Recovery

Ginkgo Tree Half Leaf-Out: Woodpeckers or Water Issues

Diagnosing Leaf Drop in Ficus Trees

Hibiscus Tree Care: Light, Fertilizer, and Pest Management for Blooms

Plants

Tree Identification: Mulberry vs. Poison Oak

Raywood Ash Leaf Drop in Phoenix: Normal Winter Dormancy

Crepe Myrtle Aphids: Sticky Leaves, White Bugs = Systemic Fix

Eliminating Invasive Tree Sprouts: Glyphosate Wipe Technique

Reviving a Declining Jasmine Tree: Light, Temperature, and Pruning

Taiwan Ficus Bonsai Leaf Drop: Need Species ID and Details

Paulownia Tomentosa: The Fast-Growing Empress Tree and the Art of Pollarding