Potted Meyer Lemon: Edema (Water Blisters), Spider Mites, and Pollination Issues—Complete Indoor Care Guide

Underside of Meyer lemon leaf with brownish raised spots

Close-up of leaf spots

Diagnosis 1: Edema (Oedema)

Brownish, slightly raised spots on leaf undersides = edema. Caused by roots absorbing water faster than leaves transpire (cool, wet soil + low light). Cells burst, forming corky spots. Not a disease.

Fix:

• Stop watering until soil dries deeply.
• Do not mist leaves—wet foliage spreads pathogens.
• See CSU edema fact sheet.

Diagnosis 2: Spider Mites

Webbing on branches/flowers = mites. Current wiping helps but won't eradicate.

Safe Indoor Treatment:

• Horticultural oil (neem oil): Non-toxic, smothers mites. Test on a few leaves first.
• Treat all nearby plants simultaneously.
• Repeat weekly 3–4 times.

Issue 3: Fruit Drop

Tiny lemons falling = lack of pollination. Indoor trees need hand-pollination (brush pollen between flowers) or a second tree for cross-pollination. Bees don't visit indoors.

Follow-Up Advice

• Water weekly max; let soil dry.
• Skip leaf misting.
• Use neem oil for mites; homemade recipes risk leaf burn—test first.
• Hand-pollinate with a small brush.