White Fuzzy Spots in Phalaenopsis Pot: Perlite, Not Pests—And Repotting Rotten Roots

Question:

Phalaenopsis in bloom >1 month, had mushy roots when received. Waited to repott. Now see white fuzzy spots (1–2 mm) around one root inside pot—not on root, not moving. Nothing on leaves. Another healthy Phal next to it, no space to separate. What are spots? What to do?

Answer:

Hi Annely,

Likely a small piece of perlite (sponge rock)—some growers add it for aeration. Perlite is superheated volcanic rock, inert, harmless. More may be deeper in pot (visible at repotting).

Be careful watering with rotten roots—allow mix to become barely moist before watering. Over-moisture worsens rot.

Until blooms die, get fresh media and possibly smaller pot. If few/no live roots, repot into smaller pot regardless of plant size—large pot + few roots = media stays wet too long, rotting remaining roots.

Jim Kawasaki
San Jose, CA