Planning reference

Fusarium Wilt vs Verticillium Wilt

Separate Fusarium wilt from Verticillium wilt before replacing tomatoes, changing soil, composting plants, grafting, solarizing, or assuming every wilted nightshade has the same problem.

What each tomato wilt signal means

Fusarium wilt
Fusarium wilt is a soilborne vascular disease that plugs water movement in susceptible tomatoes, peppers, eggplants, and related nightshades, often showing up when soils are warm and plants are carrying fruit.
Verticillium wilt
Verticillium wilt is another soilborne vascular disease with overlapping tomato symptoms, but it often develops more slowly, can appear in cooler conditions, and can be hard to separate without cultivar history or lab diagnosis.
Warm-soil, one-sided yellowing and dark vascular browning
Lower leaves that yellow on one side of a plant or one side of a leaflet, wilt during the day, recover at night, and show brown vascular streaking when the lower stem is cut point toward Fusarium wilt.
Cooler-soil, slower, more uniform interveinal yellowing
Lower leaves with pale interveinal yellowing, V-shaped or wedge-like lesions, gradual wilt, and lighter vascular browning in cooler or moderate weather point toward Verticillium wilt.
Stem scrape, crop history, and diagnostic-lab limits
Both wilts can brown the vascular tissue and persist in soil. Use resistant-variety letters, previous tomato or potato crops, root-knot nematode pressure, and lab confirmation before making long-term soil decisions.

Soilborne wilt workflow

Do not diagnose from wilt alone
Do not treat every wilting tomato, pepper, eggplant, or potato as the same problem; check lower-leaf timing, one-sided yellowing, night recovery, fruit-sizing stage, stem vascular browning, soil temperature, cultivar resistance letters, root-knot nematode pressure, drainage, crop rotation history, and whether a diagnostic lab is needed before replanting, composting, grafting, solarizing, or applying any product.
Check the crop and cultivar letters
Use tomato, pepper, eggplant, potato, or nightshade history and resistance letters such as F, FF, FFF, or V before assuming one soilborne wilt.
Cut low on the stem
Scrape or cut a lower stem to look for brown vascular tissue, then compare the pattern with leaf symptoms instead of relying on one wilted afternoon.
Separate soilborne wilt from leaf diseases and transplant stress
Early blight, Septoria, late blight, bacterial spot, drought, waterlogging, transplant shock, and root injury can all mimic or compound wilt symptoms.
Plan prevention, not rescue
Once vascular wilt is established, product cures are limited. Use resistant varieties, clean transplants, crop rotation, weed and volunteer control, soil-health practices, drainage, and sanitation for the next planting.

Use these paths

Source basis