My weeping fig (Ficus benjamina) has a clear sap on the leaves, but the plant seems healthy. Should I be worried?
The clear sticky substance is probably honeydew secreted by one of several insects. Start with a close look at the stems, undersides of the leaves and the place where the leaf stem (petiole) joins the plant stem. Check for brown bumps that can be scraped off with your finger. These are adult scale insects, a common pest of weeping figs grown indoors. Gently scrape off the scale using your fingernail or an old toothbrush. Then spray the plants with insecticidal soap or Neem to kill the translucent immature scale that are sure to be present. Continue the treatment once a week or so until the scale are no longer present. Persistence is the key to successfully controlling this pest. Aphids and mites also secrete honeydew but are less common problems on Ficus plants. Several applications, one week apart, of insectidical soap or Neem will control these pests.
Photo: Whitney Cranshaw, Colorado State University