Dracaena Massangeana (Corn Plant) Brown Spots: Fluoride, Fungus, and Light Fixes

Three Main Causes of Brown Spots

1. Fluoride/Chlorine Toxicity: Tap water chemicals accumulate in leaf tips and margins. Dracaenas are highly sensitive.
2. Fungal Leaf Spot: Phyllosticta or Fusarium—brown spots with yellow halos, often from wet leaves or high humidity.
3. Sunburn: Bleached patches from too much direct light (common in store windows).

Water Fix (Addresses #1)

• Use distilled, rain, or RO water only.
• Or let tap water sit in open container 48 hours (chlorine dissipates; fluoride does not).
• Water when top 1/3 of soil is dry. Deep soak, drain saucer.

Fungus Treatment (Addresses #2)

• Spray entire plant (leaf tops/bottoms, stems) with Lysol-type disinfectant (original scent).
• Repeat twice a week for 3 weeks. Consistency kills fungal spores.
• Improve air circulation; avoid wetting foliage when watering.

Light Adjustment (Addresses #3)

Corn plants want bright indirect light. Direct sun through glass = burn. Move a few feet back from south/west windows, or use sheer curtain. North/east windows are ideal.

General Care for Spot-Free Foliage

• Trim brown tips at an angle (cosmetic).
• Fertilize monthly at 1/4 strength spring–fall.
• Repot only when root-bound (every 2–3 years), 1–2 inches larger pot.
• Wipe leaves monthly to remove dust and inspect for pests.

When to Worry

If new growth emerges clean and spots don't spread, it's likely old damage or minor fluoride sensitivity. If new leaves show spots, re-evaluate water and light.

Switch to pure water, treat any fungus, and give it the right light—your corn plant will grow tall and elegant with minimal blemishes.