Pelargonium x hortorum · Perennial
Pelargonium rust: Improve ventilation, remove affected leaves, and isolate new plants for two weeks.
Vine weevil: Check pots regularly and apply a systemic insecticide or biological control to soil.
Powdery mildew: Ensure good air circulation and treat with a suitable fungicide if severe.
Red spider mite: Increase humidity, spray leaves with water, and use miticides if necessary.
Aphids: Squash by hand or spray with insecticidal soap or horticultural oil.