Sticky Residue on Houseplant You May Have Scale
Close up images of hard Scale on a Ficus
Soft Scale on Kentia Frand
Does your houseplant have Scale?
If you have found that your houseplant suddenly looks as if it has been sprayed down with something that looks similar to soda leaving behind a shiny sticky residue. If you have noticed pots, floors, and leaves are sticky. If you have noticed the backs of leaves, stems, and sometimes fronts of leaves have little brown, green, or tan bumps and specks. If you have noticed any or all of these things your house plant most likely has and infestation of Scale.
For the untrained eye the symptom of Scale that is usually noticed first is the sticky splatter that gets all over the leaves and floors. This sticky residue is created by the living scale on the plant, it is called Honey Dew, but before you get ready to collect and market this sweet and delicious sounding substance realize that the Honey Dew is really just a nice name for Scale "poop". Many houseplant pests (Scale, Aphids, Mealy Bug) produce Honey Dew, but for Scale it is one of the most prevalent and obvious forms of damage created by the creatures. Most people only notice the actually body of the pest itself (as seen to the right) after noticing the Honey Dew, and when the infestation has become very significant.
So what in the world is Scale anyway?
What is Scale?
When detected Scale initially looks as if it is an in-animate growth on a plant. Scale does not appear to move at all, and in most cases looks to be fused to the plant material it is attached to. It often blends in with the plant being found in very natural shades of brown, tan, and green. In spite of its sedentary nature Scale is in fact an insect. It is closely related to the Mealy bug. Scale has a hard or semi soft shell, under its shell it has a piercing mouth part on the bottom of its body. Scale uses this mouth part to bit into plant leaves and eat out the contents. Scale holds massive numbers of eggs under its shell that are in different stages of incubation. Scales is well attached to the plants it infests in most cases and, there are some Scale called crawlers that move about as juveniles until they find a good spot to settle and feed. The Honey Dew produced by the Scale is very sticky and can be damaging to floors and other household items.
Your plant is not necessarily doomed if you do find that you have a nasty case of Scale.
How to get rid of and prevent Scale on your houseplant.
Before doing anything with the Scale, check to make sure that the infected plant is not near any other plants, especially any that the Honey Dew could drip down on. Honey Dew can carry Scale eggs in it and assist in the migration of an infestation is it drops in the right spot.
Getting rid of Scale is going to require a bit of elbow grease for sure. Hand wiping will be necessary to clean the Scale bodies off of the plant. Scale must be wiped off and a reasonable amount of pressure must be applied when wiping it away in order to detach adult scale from the leaf. Using wet paper towels or baby wipes to remove the Scale is recommended, as these item are easily disposed of. Never reuse anything that was used to clean Scale off an infected plant on any other plant, doing so would very effectively spread the Scale. When wiping be sure to check the underside of leaves, leaf stems, and major plant stems. When all of the Scale Bodies have been wiped away it is beneficial to wipe leaves again with an insecticidal soap solution, neem oil, very light dish soap and water, or a solution of Dr. Bronners soap and water. Wiping again with the soaps or oils will further clean and provide a protective barrier against any young or eggs that may have been missed. Be careful to use the soap and oils very lightly and as directed. Some plants may have an adverse reaction to an overabundance of these products and some plants like ficus will have an adverse reaction to these products being used at all.
All Honey Dew should be wiped off of a plant or any surrounding areas or items that may have been touched by it.
Continued, and consistent cleaning of plants that have had Scale is really the very best defense and offense for these nasty little creatures, also generally keeping your plant stable in a healthy environment is beneficial, a strong and stable plant in the right environment is less likely to be overtaken by an infestation.
If you find that the infestation being dealt with is too prolific for cleaning to be effective, or perhaps it is on a plant that is too big or intricate to clean well, ficus are a good example you may need to resort to more serious measures. In situations like this where cleaning is not practical a systemic pesticide may be the best option, but this is only recommended if other measures are not practicle. Systemic pesticide comes in liquid, granulated, and powder forms. It is usually added to the soil directly or mixed in water and watered into the soil. Systemic pesticide is then absorbed into the plant through the roots and sent all throughout the entire plant system, causing the plant to become toxic to anything that may feed on it. Be very careful that the application directions are strictly adhered to if systemic is used. Systemic can become toxic to the plant itself, and other living creatures if used improperly.
To recap preventing and getting rid of Scale:
- Quarantine the infected plant
- Wipe away Scale bodies with precision
- Coat leaves with, Neem oil, insecticidal soap, dish or Dr. Bronner's and water solution.
- Clean up all Honey Dew on and around plant
- If all else fails use a systemic pesticide as directed.
Good luck treating your plants. For more information on other House Plant problems look into the Thoughthole Houseplant Tips and Technique articles.