When in doubt, test a small portion of the plant and wait a day or so before spraying the whole plant. Once an insecticidal soap application has dried, wash it off with fresh water. This can help prevent damage to marginally sensitive plants. As with all pesticides, avoid spraying during the hottest part of the day. Insecticidal soap has little effect on most beneficial insects, but will kill predaceous mites.
Sulfur is one of the oldest pesticides still in use today.
It is used as a miticide and also as a fungicide. Sulfur is toxic to mites but less so to insects, selectively killing mites, but doing little damage to beneficial insects. Some plants are sensitive and may be damaged by sulfur. Do not apply sulfur to plants labeled as sensitive. In addition, plant injury may result if sulfur is used during periods of high humidityor high temperatures, or in combination with horticultural oils.