Cucumber Plant Wilting: Heat Stress or Bacterial Wilt?

Set your conditions — the recommendation updates instantly.

GardenSays

Can't reliably tell Bacterial wilt (cucumber beetle-vectored) and Heat/drought stress apart from what you've described — they need different responses, so check the signs below before treating.

Status: Needs closer look
Leading possibilities: 2
Causes checked: 2

On vine wilting, 2 possible causes matched your conditions closely enough that we can't confidently rank one above the others: Bacterial wilt (cucumber beetle-vectored), Heat/drought stress.

Bacterial wilt (cucumber beetle-vectored) is one of the possibilities and can't be cured — rule it out first: Wilts during the day, recovers at night at first, then stops recovering — usually one vine at a time, spreading. Confirm it: cut the stem near the base, squeeze the cut ends together, then slowly pull apart — sticky sap that strings out like mozzarella confirms it; no other cucurbit disease does this.
This is a symptom-pattern match from your written description, not a lab diagnosis. If the plant is collapsing over days (not weeks), treat it as the worst plausible cause until ruled out.
A clear, well-lit photo (or a sample bag) to your county Extension office resolves this faster and more reliably than guessing from a description — especially when the possibilities need different treatment.

Do this this week

1.Compare your plant against each distinguishing sign above — that's how you tell Bacterial wilt (cucumber beetle-vectored) from Heat/drought stress
2.Rule out Bacterial wilt (cucumber beetle-vectored) first — it's the one that can't wait: Wilts during the day, recovers at night at first, then stops recovering — usually one vine at a time, spreading. Confirm it: cut the stem near the base, squeeze the cut ends together, then slowly pull apart — sticky sap that strings out like mozzarella confirms it; no other cucurbit disease does this.
3.Still unsure? Send a photo to your county Extension office

Calculated result · 6 verified sources · Checked 2026-07-17 · How we decide

The link reopens this exact calculation.

Why

Bacterial wilt (cucumber beetle-vectored) (can't be cured): Wilts during the day, recovers at night at first, then stops recovering — usually one vine at a time, spreading. Confirm it: cut the stem near the base, squeeze the cut ends together, then slowly pull apart — sticky sap that strings out like mozzarella confirms it; no other cucurbit disease does this. → No cure. Remove and destroy the vine before beetles spread it further; control cucumber beetles on remaining plants.

Heat/drought stress (harmless): Wilts in afternoon heat, fully recovers by next morning; soil is dry at the root zone. → Water deeply; recovery overnight confirms it was just heat, not disease.

A symptom tree can only narrow the field using the conditions it asks about — when two or more causes share the same pattern for those conditions, naming a single winner would be a guess dressed up as an answer.
The safe move when possibilities diverge this much is to rule out the worst case first, not to assume the mildest one.

When this doesn't apply

If the plant is collapsing over days (not weeks), treat it as the most severe possibility above until ruled out.
Multiple symptoms at once usually means today's top matches plus plain stress — fix watering first, then re-check.

How this was calculated

1. SymptomSource guidance
Cucumber: vine wilting — 2 known causes evaluated (extension-sourced)
2. Your conditionsCalculated result
Location on plant: lower; soil: moist. Causes whose known pattern matches these conditions rank higher — this narrows the list, it doesn't identify anything.
3. 1. Bacterial wilt (cucumber beetle-vectored)match score 3Calculated result
Distinguishing signs: Wilts during the day, recovers at night at first, then stops recovering — usually one vine at a time, spreading. Confirm it: cut the stem near the base, squeeze the cut ends together, then slowly pull apart — sticky sap that strings out like mozzarella confirms it; no other cucurbit disease does this.
4. 2. Heat/drought stressmatch score 2Calculated result
Distinguishing signs: Wilts in afternoon heat, fully recovers by next morning; soil is dry at the root zone.

Data sources

University of Minnesota Extension — Powdery mildew of cucurbits — The first sign of powdery mildew is pale yellow leaf spots, with white powdery spots forming on both upper and lower leaf surfaces that quickly expand into large blotches. (checked 2026-07-17)
University of Minnesota Extension — Bacterial wilt of cucurbits — Leaves first appear dull green, wilt during the day and recover at night; leaves eventually yellow and brown at the margins, then completely wither and die. The bacteria overwinter in the gut of striped and spotted cucumber beetles. Cut the stem near the ground and squeeze — sticky sap that strings out like mozzarella between the cut ends confirms bacterial wilt; no other cucurbit disease produces this ooze. (checked 2026-07-17)
University of Minnesota Extension — Downy mildew of cucumber, melon and squash — Yellow to pale green spots form on the upper side of the leaves, and on the underside there is a velvety grey fuzz. (checked 2026-07-17)
Cornell Vegetables — Cucumber Leaf Symptoms (cucurbit disease key) — Angular leaf spot: brown spots angular in shape (restricted by small veins) with yellow haloes, starting as pale-green water-soaked lesions with holes developing in the center. Powdery mildew: white talcum-like powdery growth on both leaf surfaces, developing first on older/lower leaves. (checked 2026-07-17)
University of Minnesota Extension — Cucurbit viruses — Virus-infected leaves often have a mottling or mosaic pattern in shades of green and yellow; leaves are often distorted, puckered or cupped; growth is stunted. It is difficult to identify the specific virus from visual symptoms alone — a plant disease clinic sample is the only way to confirm the species. (checked 2026-07-17)
University of Minnesota Extension — What's wrong with my plant? (cucumber diagnostic) — Spider mites are very small (about 1/50 inch), yellow to dark crimson with dark spots, and usually appear in late June and August in hot, dry weather. (checked 2026-07-17)

What changes this answer

Where on the plant?

Soil right now

Every change updates the answer, the math, the weekly steps and the share link instantly.

Your next decisions

Cucumber Leaves Turning Yellow

Diagnose cucumber leaves turning yellow — ranked causes, how to confirm, what to do

How Often to Water Cucumber Plants

Watering frequency and amount for cucumbers, by setting and weather

Cucumber Leaf Spots

Diagnose angular leaf spot on cucumber and tell it apart from downy mildew