What's eating my corn plant?

Corn plant shares the spider mite and scale vulnerability common to all indoor Dracaenas. Its broad leaves also attract mealybugs. Scale insects are the most persistent problem, often going unnoticed on the thick canes until populations are large. Check cane joints and leaf undersides regularly, and treat with horticultural oil at the first sign.

Hard brown bumps on canes and leaf midribs; sticky honeydew dripping onto lower leaves; sooty mould. Scrape off with a soft toothbrush; apply horticultural oil or neem oil; repeat every 10 days for at least three cycles.

Fine pale stippling across broad leaves; webbing on undersides; leaves yellow and drop in severe cases. Wipe leaves with a damp cloth; raise humidity; apply insecticidal soap or neem oil weekly.

Cottony white masses at leaf bases and in cane crevices; leaf yellowing and premature drop. Apply isopropyl alcohol with a cotton swab; follow with neem oil spray; soil drench for root mealybugs if plant declines despite treatment.