Cottony Growth on Hibiscus: Woolly Aphids or Scale?

Cottony Growth on Hibiscus: Woolly Aphids or Scale? White, cotton-like masses on hibiscus stalks near buds, accompanied by flower failure, are typically woolly aphids or cottony scale insects. Both produce waxy filaments

Borer Damage and Scale on Kwanzan and Weeping Cherry Trees

Borer Damage and Scale on Kwanzan and Weeping Cherry Trees Amber resin (gummosis) oozing from the trunk or branches of cherry trees typically indicates borer activity—beetle or moth larvae tunneling beneath the bark. Whi

Oak Leaf Blister on Water Oak: A Common Spring Disease

Oak Leaf Blister on Water Oak: A Common Spring Disease Brown, blister-like spots on water oak leaves that cause curling and early drop are caused by the fungus Taphrina caerulescens. Infection occurs during cool, wet spr

Phyllosticta Leaf Spot on Autumn Blaze Maple: Cosmetic, Not Critical

Phyllosticta Leaf Spot on Autumn Blaze Maple: Cosmetic, Not Critical Small, black, elevated spots on the undersides of Autumn Blaze maple leaves that powder when crushed are the fruiting bodies of Phyllosticta minima, a

Mealybugs and Pink Mealybug on Hibiscus: Organic Solutions

Mealybugs and Pink Mealybug on Hibiscus: Organic Solutions Shriveling leaves around flower buds, failure of blooms to open, and a white powdery substance in the flower center are hallmarks of mealybug infestation—particu

Scale and Woolly Aphids on Magnolia: Identification and Control

Scale and Woolly Aphids on Magnolia: Identification and Control White bumps on magnolia stems and a sticky residue (honeydew) on leaves indicate an infestation of scale insects and/or woolly aphids. Both pests suck plant

Slime Flux (Wet Wood) on Maple Trees: A Bacterial Condition

Slime Flux (Wet Wood) on Maple Trees: A Bacterial Condition Black, vertical streaks on a maple trunk that appear wet, follow bark cracks, and may emit a foul odor are classic symptoms of slime flux (wet wood). This condi

Sooty Mold on Mugo Pine: Treating the Underlying Insect Problem

Sooty Mold on Mugo Pine: Treating the Underlying Insect Problem Blackened branches on one of two similarly situated mugo pines usually indicate sooty mold—a black fungus growing on honeydew excreted by sap-feeding insect

Adjusting Watering for Ginkgo Trees with Brown Leaves

Adjusting Watering for Ginkgo Trees with Brown Leaves Ginkgo trees showing brown foliage after frequent watering (every 3 days) combined with heavy seasonal rain are likely suffering from waterlogged roots. Ginkgos are d

Scale Insects on Boxwood: Identification and Organic Control

Scale Insects on Boxwood: Identification and Organic Control Long, brown, raised ridges on boxwood branches that scrape off with a fingernail, accompanied by heavy leaf drop, are classic signs of scale insects. These pes

Sudden Aspen Decline: Understanding Aspen Die-Off

Sudden Aspen Decline: Understanding Aspen Die-Off When mature aspen trees lose leaves on most branches, show crown thinning, and fail to leaf out fully, Sudden Aspen Decline (SAD) is a prime suspect. This phenomenon has

Golden Raintree Decline: Stress and Possible Root Disease

Golden Raintree Decline: Stress and Possible Root Disease Rapid browning of lantern-shaped seed pods, sporadic leaf yellowing, and progressive defoliation in golden raintrees planted in difficult urban conditions (compac

Troubleshooting Small, Drying Figs on Mission Fig Tree

Troubleshooting Small, Drying Figs on Mission Fig Tree When Mission figs remain thumb-sized and dry up instead of plumping and ripening, the cause is often environmental or cultural rather than a specific disease. The tr

Early Fall Color on Aristocrat Pear Trees: Causes and Solutions

Early Fall Color on Aristocrat Pear Trees: Causes and Solutions When an Aristocrat pear tree displays premature red leaf coloration while neighboring trees remain green, the issue is often physiological rather than patho

Managing Powdery Mildew on Leucothoe

Managing Powdery Mildew on Leucothoe A whitish, powdery coating on leucothoe leaves that progresses to yellowing and leaf drop is characteristic of powdery mildew, a common fungal disease in shady, humid locations. The f

Diagnosing White Fuzzy Growth on Crepe Myrtle

Diagnosing White Fuzzy Growth on Crepe Myrtle After periods of heavy rain, crepe myrtles often develop a white, powdery or fuzzy coating on new shoots. This is typically powdery mildew, a fungal disease favored by humid,

Victoria Plum Tree Disease: Identifying and Managing Common Problems

Victoria Plum Tree Disease: Identifying and Managing Common Problems When Victoria plum fruits develop a scale-like coating, exude gelatinous droplets, and eventually turn dark blue, shrivel, and rot, two primary issues

Ficus White Leaf-Base Dots: Scale or Natural? Alaska Indoor Care

Case Alaska: New ficus (weeping fig) houseplant. Months healthy, new growth. Now: few leaves dropped, small waxy white dots at base of ~60% leaves. Indirect sun, potted. Two Possibilities CauseClues Natural (cystoliths

Cleveland Pear Sudden Death: Fire Blight or Regional Decline?

Case Cleveland pear: leaves dead, small limbs brittle. Last year beautiful. Will it return? Two Scenarios (Steve) ScenarioSymptomsAction Regional DeclinePurple/red fall color over canopy, leaf drop. No pathogen found.

Mature Carrotwood Slime Flux: Arborist Drilling Plan Questioned

Case 40-yr-old carrotwood (LA): black sap oozing from conical hole 2 ft out on major limb. Arborist: slime flux, drill vertically through limb to dry it. Owner approved. Asks if correct. Expert Validation Certified arb