If your plants are suddenly struggling, diseases may be the cause.
Use the Dirty Dozen Quick Garden DISEASES chart and Triage section below to quickly identify common diseases and take immediate action before damage gets out of hand.
If you suspect pests are the culprit, see Garden PEST Identification Guide: The Dirty Dozen
Quick DISEASE Triage (Start Here)
Anthracnose
Sunken dark spots on fruit or leaves. Fruit may rot quickly once infected.
Remove infected fruit and use mulch to prevent soil splash. Harvest promptly.
Anthracnose → View Full Guide
Bacterial Spot / Speck
Small dark spots on leaves, often with yellow halos. Can appear on fruit as well.
Remove affected leaves and avoid overhead watering. Do not handle plants when wet.
Bacterial Spot / Speck → View Full Guide
Blight
Rapid browning, spotting, or collapse of leaves and stems, especially in wet weather. Can spread quickly.
Remove infected material immediately. Keep foliage dry and remove plant if spreading fast.
Blight → View Full Guide
Damping Off
Seedlings suddenly fall over or collapse at the soil line shortly after sprouting.
Increase airflow and reduce watering. Restart with clean soil and containers.
Damping Off → View Full Guide
Downy Mildew
Yellow patches on top of leaves with gray or fuzzy growth underneath. Spreads quickly in humid conditions. Remove infected leaves and avoid overhead watering. Improve airflow immediately.
Downy Mildew → View Full Guide
Gray Mold (Botrytis)
Soft brown spots with fuzzy gray mold, especially in cool, damp conditions. Common on flowers and fruit.
Remove affected parts and improve airflow. Keep plants dry.
Gray Mold → View Full Guide
Leaf Spot
Brown or black spots on leaves, often with yellow halos. Usually starts on lower foliage.
Remove affected leaves and mulch soil to prevent splash. Keep water off foliage.
Leaf Spot → View Full Guide
Powdery Mildew
White powdery coating on leaves, usually starting on older growth. Leaves may curl or yellow over time.
Remove infected leaves early and improve airflow. Start a weekly milk spray.
Powdery Mildew → View Full Guide
Root Rot
Plants wilt despite wet soil. Growth slows and leaves yellow. Roots may appear brown or mushy if checked. Improve drainage and reduce watering. Remove severely affected plants.
Root Rot → View Full Guide
Rust
Orange, rust-colored spots appear on leaves, often on the underside. Leaves may drop early.
Remove infected leaves and avoid wetting foliage. Improve airflow around plants.
Rust → View Full Guide
Viral Diseases
Mottled yellow-green patterns, distorted leaves, and stunted growth. Spread by insects.
Remove affected plants and control insect pests like aphids.
Viral Diseases → View Full Guide
Wilt (Fusarium / Verticillium)
Plants wilt during heat and do not recover, even when watered. Often affects one side first.
Remove the plant and avoid replanting the same crop in that area.
Wilt → View Full Guide
