Potato Scab: Rough Spots on Tubers
Stem & Roots problem · common pattern reported by gardeners · verify locally
What you'll see
- Raised rough brown patches
- Corky scabs on skin
- Still edible if peeled
Most common causes
- Scab bacteria in alkaline soil
- Dry soil during tuber set
- Fresh manure
How to fix it
- Peel affected tubers
- Improve soil organic matter
Prevention: Keep soil pH below 6.5 (acidic) Even moisture during tuber set Avoid fresh manure
More Potato problems
Grow Potato with confidence
Open the Potato growing guide → · Planting calendar · Pest & problem diagnoser
ZoneFig content reflects widely published extension-service and gardening guidance. Symptoms and causes are common patterns, not a diagnosis for any individual plant — verify locally and treat conservatively.