What is this sticky substance all over the table, floor, and lower leaves of my houseplant?


What is this sticky substance all over the table, floor, and lower leaves of my houseplant?


Honeydew is a sticky, sugar-rich substance produced by insects that suck sap from plant leaves and stems.  This excretion often coats lower leaves, tables, and floors and when severe, may promote the growth of black sooty mold. 

Honeydew is caused by several different common houseplant pest insects

Several common insect pests produce honeydew on indoor plants including scale, mealybug, and aphids.  Inspect leaves and stems for scale insects which look like small bumps or scales clustered along stems and on the undersides of leaves.  If cottony, white masses are found clustered along leaf axils or on the undersides of leaves, then plants are infested with mealybug.  Aphids are small, soft-bodied insects, often green, brown, or reddish in color and found clustered on growing points, underneath leaves, along stems, and on flower buds.

Managment Options

To get rid of honeydew, you have to control the insects that cause it.  Control of these insects can be difficult.  Start with a good rinse or wipe-down using a damp cloth to remove honeydew, sooty mold, and dislodge insects like aphids and mealybug.  Scale and mealybug can be physically removed with a thumbnail and when infestations are small, dabbed with a cotton swab dipped in rubbing alcohol.  Prune out heavily infested leaves and stems.  Consider the use of an insecticide such as insecticidal soap, neem, horticultural oil or pyrethrin.  Check the label to be sure both the plant species and the pest insect are listed and always follow label directions.  Multiple, thorough applications of insecticide on a weekly basis for 4 to 6 weeks will be needed for complete control.  If plants are heavily infested, it may be better to discard the plant before other houseplants are infested.

Answered by
  • Specialist
  • Consumer Horticulture Extension
Last updated on
March 19, 2024