Botanic Garden >> Gardening > >> Question and Answer >> Plant Diseases

Scale or Powdery Mildew on Lilac: Neem Oil vs. Atomic Grow

White, non-powdery deposits on lilac leaf undersides that resist soap/water, with dried top leaves, indicate scale insects (attached to vulnerable lower surface) or powdery mildew. Both are difficult to eradicate.

Treatment Comparison

Neem oil: Smothers scale by suffocation; does not improve plant health.
Atomic Grow: Cleanses leaves to the micron, stimulates growth, and repels insects by raising brix. Available at crowleynursery.net.
Both are natural and pesticide-free.

Atomic Grow provides dual action: pest removal and plant stimulation.

Plant Diseases: Lilac Borer Infestation: Diagnosing Without Photos and Treatment Options; Lilac Sudden Leaf Curl and Decline: Multiple Possible Diseases + Neighbor’s Overwatering; Lilac in California: Humidity, Leaf Miner, and Pruning Rules; Black Sooty Mold on Holly: Control the Sucking Insects First; Ladybugs on Lilac: Beneficial Predators, Not Pests; Powdery Mildew on Lilac: Identification and Treatment; Butterfly Bush Lace-Like Leaves: Identify Damage Before Treating; Leaf-Eating Insects: Aphids, Beetles, and Millions More; Sparse Leaves on a Flowering Lilac: Could It Be Armillaria Root Rot?; Rescuing Drought-Stressed Lilac in NE Ohio

Garden Articles

Viburnum Leaf Beetle Devastating Snowball Bushes

White/Gray Leaves on Japanese Red Maple: Need Photo

Lilac Bush Leaf Scorch After June Planting: Transplant Shock

Lilac Leaf Spots and Curl: Need Photo for Accurate Diagnosis

Lilac Curled Leaves with Black Powder: Aphids and Sooty Mold

Sooty Mold on Camellia Hedge: Caused by Scale Insects

New Lilac Bush Has Crinkled, Blackened Leaf Edges — Should You Worry?

Plants

Scale Insects Masquerading as Fungus on Lilac

Roundup Drift on Lilacs: Recovery Possible

Yellow Leaves with Holes: Insects, Watering, and the Two-Knuckle Test

Overwintering a Potted Lilac on a Balcony: Zone-Dependent Advice

Tibouchina Winter Damage in Florida: Patience for Spring Recovery

Lilac Bush Budding in Late July: Stress or Second Bloom?

Lilac and Burning Bush Pests: Scale, Spittlebug, Mites