Plant guide:ð Lemon Tree
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Leaves
Oedema (Water Blisters) on Lemon Tree Leaves
Commonly affects: Citrus limon (Lemon Tree)
Small, corky, blister-like bumps develop on the undersides of leaves, sometimes turning brown or rust-coloured over time.
Potential Causes
- 1Oedema, a physiological condition (not a disease) caused by roots taking up water faster than leaves can transpire it, causing cells to swell and rupture
- 2Overwatering combined with high humidity and low light, conditions that reduce transpiration
- 3More common in indoor or greenhouse-grown citrus during cloudy, humid stretches
Solution Steps
- 1Improve air circulation and light exposure to encourage more active transpiration
- 2Water more moderately during cloudy, humid, or cool stretches when transpiration naturally slows
- 3Understand that oedema is a physiological response, not an infection, and existing blisters won't heal but new growth will be unaffected once conditions improve
- 4Avoid overwatering, particularly during periods of reduced light or high humidity
Prevention Tip
Oedema is a physiological water-balance issue rather than a disease â the blisters themselves are permanent, but adjusting watering and light prevents new ones forming.
