Sticky Leaves on Indoor Plants: What Causes Sticky Plant Stuff?

If you are a houseplant owner, maybe you have experienced white sticky stuff on plants or sticky residue on plant leaves.

There are many causes for wet or sticky plants, and these incidents can present quite a hassle for any plant owner. What causes it, and how do you handle a plant with sticky leaves?

many times you find sticky leaves houseplants like the Ficus. — You often find leaves on houseplants with sticky stuff covering them like the Ficus

Question: My houseplant has sticky leaves! It’s the only way to describe the foliage. No matter what I try the cure never seems to happen.

Should I get rid of the ficus plant? Do you know if it’s a disease or know what causes the sticky plant leaves and the cure? April, Oregon

Answer: April, a sticky substance on the leaves, is one houseplant problem that isn’t unique.

Since you did not mention the indoor houseplant you’re experiencing the sticky issue on, here’s a general overview of the problem.

After you’ve brought your new plant home and it’s gone through the:

Acclimation process of leaf drop
Adjusting to a new watering schedule
And happy with its new indoor life

… it seems to happen. A sticky sap on the leaves and plant foliage.

One day on the way to grab your breakfast, you notice the area around your indoor plant is tacky or sticky, with a sticky couch, sticky floors, and sticky leaves on plants.

You step back, scratch your head and ask a few questions…

Did the kids spill a soft drink?
What caused it?
Do I have enough time to clean the sticky substance up?

Cause of Sticky Leaves on Indoor Plants

The cause of the sticky leaf is normally because of scale insects on the plant. Plant scale feeds and suck plant sap (the plant juices or nectar) out of houseplants.

The sticky residue on plants, leaves, and the floor is what they secrete and is a sticky substance called honeydew or sticky honeydew.

A tall, green fiddle leaf fig plant with large, violin-shaped leaves on a white background.

The sticky, shiny honeydew may eventually develop into a sooty mold, a black, powdery fungus that covers the leaf surfaces with a grey, powdery coating.

Too often, people only look at the top leaves. Check plants by looking at the undersides of leaves and on the stems for slight bumps of tan, black or brown color with a waxy coating and sticky secretion.

You’ll find infested plants with plant scale, soft scales, or cottony masses of mealybugs hiding in out-of-the-way places and out of sight where they can be left alone.

Houseplant Sticky Leaves Treatment – Controlling Scale

Generally, controlling plant scale bugs isn’t a big problem. Scale “breathes” through their “armor.” The easiest way to kill the scale is by suffocation.

There are several natural methods to get rid of the scale insects on plants indoors.

In the early stages of a light infestation:

Mix 1 teaspoon of DAWN dish detergent into 1 quart of warm water
Dip a cotton swab into the dish detergent / warm water mixture
Wipe the area down completely

also

Place the mixture into a spray bottle for large infestations and spray the entire plant with the mixture, completely coating the infested areas.

The dish detergent “clogs” or disrupts the plant scale pests’ ability to breathe.

Other additions to the spray mixture include:

A good plant insecticidal soap spray. The most popular plant soap goes by the name “Safer Soap” and works well if the infestation of scale isn’t extensive.
Another “safe option” is to try Neem oil spray for plants. Neem oil is a great overall natural product that can take also get rid of spider mites and even fleas on pets.
Add a safe horticultural oil will do the trick. A word or warning – When applying any chemical, indoors or outdoors, do it carefully and follow the label directions exactly.

Before attempting to handle the pest issue check with your local nursery or garden center – and remember … FOLLOW THE LABEL.

NOTE: I would use neem oil or insecticidal soap on indoor plants. The horticultural oil is better for outdoor plants.

Outdoors the sticky residue usually is accompanied by sooty mold. As mentioned above, horticultural oil, neem oil, and insecticidal soap can all be used outdoors.

However, do not apply when temperatures are over 85° degrees Fahrenheit, and beware that these controls will also kill natural predators.

A person's hand holding a damp cloth and wiping the leaves of a Ficus plant. The leaves are shiny and green.

Systemic Control

Pest control with a spray indoors, especially in public areas, adds an additional risk. Many interior landscaping companies control plant scale and other pest problems with systemic insecticide chemicals.

Systemics work through the root system. The chemical for control is normally applied to the soil or buried in the soil where the plant absorbs the chemical through the root system and distributes the chemical throughout the plant.

As the scale insect, mealybug, spider mite, leafhoppers, and other pests (sticky bugs) feast on sucking the plant’s juices out, they take the chemical into their bodies, killing them. The systemic pesticide process takes time – six to eight weeks is not uncommon.

The systemic process is primarily used on large trees like ficus in hotels and malls.

Our Recommended Natural Pest Control Solutions For the Home and Garden

Neem Plant Insecticide – Details on Neem Oil Pest Spray
Diatomaceous Earth – Food Grade – More on using DE here
Bacillus thuringiensis Bt
Insecticidal soap – More on insecticidal soap here
Beneficial Insects – Ladybugs, Predatory Mites, bees, waps, and Green Lacewing

For more info on these recommended products, read our detailed review here.

How to Clean Up the Sticky Liquid Stuff

Cleaning the sticky stuff off furniture versus the floor can get a little tricky.

First, frequently rinse and clean up as much of the sugary, sticky honeydew goo as you can.

Start by using VERY WARM water, apply to the area with a damp cloth, or mop frequently rinse in HOT clean water.

Some professionals recommend using Murphy’s Oil Soap, and others like rubbing alcohol and swabbing the area with a soft cloth.

This will remove any eggs or young scale insects or mealybugs.

Make sure you test your cleaning potion on an “inconspicuous area” before you start pouring it on. You could discolor the material or strip off the furniture finish.

For good plant health, the most important thing to remember is maintenance – once you have control, maintain it by regular scouting of your plants for pests and plant diseases.

Growers always keep on the lookout for ants. Ants are great farmers. Ants farm aphids and scale insects for the honeydew they produce.

Finding potential problems early helps prevent really big problems you’ll have to deal with later, not to mention the sticky floors and furniture.