Madagascar Jasmine Troubles: Yellow Leaves and Purple Spots Explained

Your Madagascar jasmine (Stephanotis floribunda) shows classic signs of two related problems: overwatering and fungal leaf spot.

Diagnosing the Symptoms

• Yellowing leaves: Often indicates root stress from soggy soil, even in clay pots.
• Purple spots with dark centers: Classic fungal leaf spot, encouraged by wet foliage overnight.

Why Clay Pots Can Still Hold Too Much Water

While clay is porous, potting soil can retain excess moisture if drainage is poor or watering is too frequent. The "finger test" (water only when top inch is dry) matters more than pot material.

Treatment Plan

1. Adjust watering: Water deeply but only when soil is dry 1-2 inches down. Never water after late afternoon.
2. Improve drainage: Ensure the pot has adequate holes and a layer of gravel at the bottom.
3. Apply fungicide: Spray with copper fungicide, chlorothalonil (Daconil), or myclobutanil to halt fungal spread.
4. Increase air circulation: Space plants apart; avoid crowding.

With drier foliage going into night and proper drainage, new growth should emerge clean and healthy.