Maranta Red Prayer Plant with Brown Spots? Diagnose Fast (US Guide)

Identify the Spot Type

• Brown spots with yellow halos: Bacterial leaf spot (Pseudomonas). Remove infected leaves, isolate plant, apply copper fungicide.
• Brown crispy spots, no halo, scattered: Tap water fluoride/chloramine damage. Switch to distilled water.
• Brown spots starting at leaf tips: Low humidity. Add humidifier.
• Brown stippling with silver streaks: Thrips. Inspect undersides with magnifier.

Treatment by Cause

Bacterial: Cut affected leaves with sterilized scissors. Move to better airflow. Spray with copper fungicide (Bonide) weekly for 3 weeks.

Water quality: Flush soil with distilled water, switch all future watering.

Humidity: Maintain 50%+ with humidifier, NOT misting (Marantas are prone to fungal issues from wet leaves).

Optimal Maranta Conditions

• Bright indirect light, 200–400 fc.
• Distilled or rainwater only.
• Humidity 55–65%.
• Soil consistently lightly moist (not wet).

Frequently asked questions

Are Marantas pet-safe?

Yes — ASPCA lists Maranta leuconeura as non-toxic to cats and dogs.

Why do Maranta leaves fold up at night?

Nyctinastic movement — totally normal. The leaves fold like 'praying hands' at night and unfurl in the morning. A healthy Maranta does this nightly.

Sources and references

• Maranta Care — University of Wisconsin–Madison Extension

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