Plant diseases can be caused by pests, fungi, bacteria, viruses or nutritional deficiencies. Correctly identifying the cause is essential to apply the right treatment and prevent the problem from spreading.

All Plant Diseases | Complete Guide 2026

Pests

Scale Insects

Spider Mites

Whiteflies

Mealybugs

Fungus Gnats

Aphids

Thrips

Root-Knot Nematodes

Leafminers

Broad Mites

Slugs and Snails

Caterpillars

Mealybugs

Armored Scale Insects

Fungal

Powdery Mildew

Root Rot

Black Spot

Gray Mold (Botrytis Blight)

Anthracnose

Sooty Mold

Fusarium Wilt

Damping Off

Rust

Leaf Spot

Downy Mildew

Pythium Root Rot

Southern Blight

Verticillium Wilt

White Mold

Phytophthora Root Rot

Phytophthora Blight

Canker

Crown Rot

Alternaria Leaf Spot

Septoria Leaf Spot

Cercospora Leaf Spot

Gray Mold (Botrytis Blight)

Diplocarpon

Colletotrichum liriopes

Powdery Mildew

Botrytis

Drepanopeziza

Pestalotiopsis

Pseudocercospora

Nutrient Deficiency

Phosphorus Deficiency

Potassium Deficiency

Iron Deficiency

Magnesium Deficiency

Nitrogen Deficiency

Calcium Deficiency

Sulfur Deficiency

Zinc Deficiency

Boron Deficiency

Manganese Deficiency

Nutrient Deficiency

Environmental

Low Light Stress

Underwatering

Low Humidity Stress

Edema

Sunburn (Sun Scorch)

Leaf Tip Necrosis

Heat Stress

Salt Buildup

Cold Damage

Overfertilization

Root-Bound

Poor Air Circulation

Soil pH Imbalance

Chemical Burn

Transplant Shock

Overwatering

Lack of Light

Mechanical Damage

Water Deficiency (Underwatering)

Bacterial