Common Pests of Sage Plants and How to Control Them

Overview

Sage is an attractive perennial herb with leaves used in cooking. It can reach over 2 feet tall, with foliage in purple, green, variegated, or gold depending on variety. All sage types are vulnerable to several insect pests.

Sweetpotato Whitefly (Bemisia tabaci)

Despite its name, this pest attacks 500+ plant species including sage. They pierce leaves and suck sap, causing wilting, leaf drop, and plant decline. Heavy infestations can kill the plant. They excrete honeydew, attracting ants and sooty mold, and can transmit diseases. Spray insecticide on leaf undersides where larvae hide; repeat as needed. Rinse leaves before consumption. Note: these whiteflies are difficult to control chemically (University of Hawaii).

Red and Black Flat Mite (Brevipalpus phoenicis)

These mites attack leaf stems first, then leaves, feeding on juices and eventually killing the plant. Early signs: leaf wilt, brown/deformed leaves, inner tissue death. Feeding creates holes and scabs. Susceptible to insecticides; heavy infestations may need second application. Tropical insects—they don't survive cold climates. Wash leaves before use.

Greenhouse Whitefly (Trialeurodes vaporariorum)

Similar to sweetpotato whitefly but smaller. Worldwide distribution; feeds on sage sap. Damage often invisible except for general decline and honeydew residue. Unfortunately resistant to several synthetic insecticides. University of Hawaii recommends insecticidal soaps or oils instead. Repeat applications as needed; wash leaves thoroughly before consumption.