- Root-knot nematodes: Swollen, knobby areas on a stunted root system. Discard affected plants, pots, and soil.
- Foliar nematodes: Dark brown dead patches bounded by major leaf veins. Frequently seen on species and varieties of Peperomia and bird’s nest fern.
- Soft rot (Erwinia sp.): Mushy decay of fleshy plant parts. Discard affected plants; space remainder. Keep foliage and stems dry; avoid splashing water. Sterilize soil and pots before reusing.
- Fungal leaf spots (Leptosphaeria, Colletotrichum, Myrothecium, Fusarium): Brown dead spots of various sizes on foliage, typically exhibiting fungus sporulation on the dead area. Generally controlled by keeping foliage dry to prevent infection. Wet plant surfaces (e.g., water in the whorl of dracaenas) promote fungal infection.
- Stem rot at soil line (Rhizoctonia, Sclerotium rolfsii, and Sclerotium delphinii): Brown stem discoloration, sometimes showing black or brown sclerotia or white to tan mycelium of the causal fungus on the dead area.
- Water mold root or leaf rot (Pythium, Phytophthora): Black to brown portions of plant in a state of soft, wet decay. Pothos is especially susceptible to Phytophthora.