Planning reference

Early Blight vs Septoria Leaf Spot

Separate tomato early blight from Septoria leaf spot before pruning, spraying, saving seed, removing plants, or blaming every lower-leaf spot on the same disease.

Problem diagnostic

Early Blight vs Septoria Leaf Spot cockpit

Start with spot pattern, lower-leaf splash history, pycnidia, fruit or stem lesions, wet foliage, mulch, airflow, and pruning timing before naming tomato leaf spots.

Bullseye rings and black pycnidia need different proof before pruning or spraying tomato leaves.
  1. 1 Early blight clues Bullseye rings, yellow halos, older lower leaves, and stem or fruit lesions.
  2. 2 Septoria clues Small gray-tan spots, dark borders, black pycnidia, and lower-leaf splash spread.
  3. 3 Leaf-spot proof Check spot pattern, pycnidia, wet foliage, mulch, airflow, and pruning timing.
Spot pattern
Bullseye/pycnidiarings, halos, gray centers, and black fruiting bodies
Spread cue
Splashwet lower foliage and soil splash move both problems
Action cue
Dry workprune after confirming lesion type and dry foliage

What each tomato leaf signal means

Early blight
Early blight is a tomato and eggplant fungal disease that usually starts on older lower leaves as brown lesions with yellow halos, then develops concentric bull's-eye rings and can move to stems or fruit.
Septoria leaf spot
Septoria leaf spot usually starts on lower tomato leaves as many small circular spots with tan or gray centers, dark borders, and tiny black fruiting bodies visible in older lesions.
Bull's-eye lesions and fruit spots
Concentric rings, larger leathery brown spots, stem lesions, or sunken dry fruit spots near the stem end point more strongly toward early blight than Septoria leaf spot.
Small gray spots with dark borders
Small round spots with gray centers, dark edges, and black pycnidia across lower leaves point more strongly toward Septoria, especially when first fruit is forming and foliage stays wet.
Lower leaves, splash, airflow, and pruning
Both diseases often start near the soil line after splashing water or wet foliage, so spacing, mulch, pruning lower branches, watering at the base, and removing infected leaves matter before fungicide decisions.

Tomato leaf-spot workflow

Check spot shape before spraying
Do not treat every tomato leaf spot the same way; check whether spots have concentric bull's-eye rings, tiny black fruiting bodies, tan or gray centers, yellow halos, fruit or stem lesions, lower-leaf splash history, wet foliage, plant spacing, mulch, and disease-resistant variety notes before pruning, spraying, saving seed, or removing plants.
Start with the lowest leaves
Look first at older lower leaves and the soil splash zone. Early blight and Septoria commonly begin there, while other problems may start higher, move faster, or affect fruit differently.
Keep foliage dry and open
Water at the base, avoid overhead irrigation, stake or cage plants, improve airflow, and prune the lowest established branches when plants are fruiting.
Remove infected tissue carefully
Remove infected leaves during the season and clean up tomato debris at the end of the season so spores do not stay concentrated around next year's plantings.
Use fungicides only as protection
Copper or other labeled fungicides may slow severe recurring disease when used early, but they do not reverse infected leaves; follow the label and use cultural controls first.

Use these paths

Source basis