Scale insects hide in plain sight — their waxy shell makes them look more like a plant blemish than a living pest.
Spotting an Infestation
Scale insects appear as small, immobile brown, tan, or white bumps clustered along stems and leaf undersides. A sticky residue called honeydew on nearby leaves, sometimes followed by a black sooty mold growing on it, is often the first visible clue before the scale itself is noticed.
Treating Light Infestations
Scale can often be scraped off by hand with a soft brush or fingernail on smaller plants, or wiped away with a cloth dipped in soapy water. Horticultural oil smothers both the adults and the young "crawler" stage, and is one of the more effective organic treatments once applied thoroughly.
Catching the Vulnerable Crawler Stage
Young scale crawlers, active for a short window before they settle and form their protective shell, are far more vulnerable to treatment than mature scale. Timing an oil or soap spray to this stage — often in late spring — gives noticeably better results.
