What's eating my xanadu philodendron?

Thaumatophyllum xanadu is one of the more pest-resistant Philodendrons, but spider mites and mealybugs will still move in during dry spells or after repotting stress. Its dense, deeply lobed clump of leaves provides ideal hiding spots for mealybugs — inspect leaf axils at soil level during every watering.

White woolly masses at leaf bases and deep in the dense clump; slow growth and sticky residue near soil level. Use an alcohol-soaked swab to treat each cluster; drench surrounding soil with diluted neem solution; repeat weekly for 4 weeks.

Fine pale speckling on leaves; thin webbing between lobes; becomes serious in centrally heated rooms in winter. Shower the plant thoroughly, then spray neem oil or insecticidal soap to all leaf surfaces weekly until clear.

Adult gnats hover around the soil; larvae feed on fine roots, causing wilting and poor growth — especially in overwatered, peat-heavy mixes. Allow the top 2 inches of soil to dry between waterings; apply Bacillus thuringiensis var. israelensis (Bti) soil drench; use yellow sticky traps to catch adults.