
Ever wonder why your bonsai tree has sticky leaves? This is a common occurrence that can be caused by many different things.
Whatever the cause, this blog post will help you identify what it might be and how to fix it so you can have happy bonsai trees with shiny leaves!
Reasons Why a Bonsai Tree Have Sticky Leaves
The most common cause of sticky leaves on a bonsai tree is either aphids or scales. These two of the most common garden pests on bonsai trees, can release a sticky substance called honeydew onto the leaves.
- This will leave your tree coated in an unattractive layer of gooey substances that looks quite unpleasant to touch! Luckily there are ways you could treat aphids or remove their eggs from around your plants before they do too much damage.
- Scale insects can also be dealt with by using an insecticidal soap spray. Always be sure to read the product label carefully and follow the instructions, as some soaps are not safe for use on bonsai trees.
If you believe that your tree may have been infected with a fungal disease, then one of the best ways to save your bonsai is to prune away the leaves that are affected. If you don’t, then it would speed up the infection and shorten the life of your beloved bonsai collection.
What are Aphids
Aphids are tiny little insects that live on the sap of plants. They can be green or black or brown or pinkish and they often cluster together in big groups so they look like really bad acne on your plant!
- Aphids can be found virtually anywhere there is vegetation—grass, trees, flowers, gardens. They are even known to hitch a ride on passing animals in order to spread to new areas.
- Aphids are sap suckers and they can cause damage to the plants they are feeding on by sucking out the plant’s juices. This makes the leaves of the plant turn yellow and wilt. In extreme cases, aphids can kill a plant.
Aphids also produce a sticky, honeydew substance that can attract ants and other insects. This honeydew can also lead to the growth of black sooty mold on the leaves of the plant.
Aphid Control
There are several ways to control aphids:
- Natural predators such as ladybugs, lacewings, and parasitic wasps can help keep aphid populations in check.
- Remove and destroy infested plants.
- Use a horticultural oil or insecticidal soap to kill the aphids.
If all of these methods fail, you can use a chemical pesticide such as malathion.
It is important to note that if you use a chemical pesticide, there may be repercussions. If bees pollinate plants that were previously sprayed with malathion and then feed on the flowers, they could die.

What are Scales
Scale insects are small, oval-shaped creatures that attach themselves to the stems or leaves of plants. They can be red, brown, black, or white and they often look like bits of dried paint or plaster on the plant.
- Scale insects suck sap from the plants they are feeding on and this can cause the leaves to yellow and wilt. They also produce a sticky honeydew substance that can attract ants and other insects. This honeydew can also lead to the growth of black sooty mold on the leaves of the plant.
- Scales are controlled in much the same way as aphids—using natural predators, removing plants that are infested, applying horticultural oil or insecticidal soap, and if all else fails, using a chemical pesticide such as malathion.
Many people prefer not to use chemicals on their plants because they are concerned about the effects that these pesticides can have on children, pets, beneficial insects such as bees, and wildlife. If you choose to use malathion or other pesticides, it is important to note that they may have negative effects on the environment.
Scales Control
In order to control the scales you will need to do the following:
- Apply a horticultural oil or insecticidal soap to kill the insects.
- If these methods fail, use a chemical pesticide such as malathion.
- Natural predators such as lacewings and ladybugs can help keep scale infestations in check.
Identifying if a Bonsai Tree has Aphids and Scales
It is important to be able to identify if your tree has Aphids or Scales because another insect, the Fungus gnat, greatly enjoys eating scale insects and aphids. If you have an infected plant with one of these pests, you will want to treat it as soon as possible.
There are a few different ways to identify if your Bonsai tree has Aphids or Scales.
- One way is to look at the leaves of your tree and see if there are any tiny, black bugs on them.
- Another way is to look at the stems of your tree and see if there are any small, white bumps on them.
If you see either of these things, then your tree has Aphids or Scales and you will want to treat it as soon as possible.

Symptoms of Bonsai Trees Infested by Aphids and Scales
There are many symptoms of Bonsai trees infested by Aphids and Scales.
- One way is to look at the leaves of your tree and see if they are curling or crinkled. If this is the case then your Bonsai tree has probably been infected for some time now.
- Another symptom is that you might see black spots on the leaves.
- A final symptom is that your Bonsai Tree might be drooping or even losing its leaves.
If you see any of these symptoms than you will want to treat your tree as soon as possible because it might fall ill and die if not treated right away.
How to Treat Bonsai With Scales and Aphids?
Scale insects are soft-bodied, immobile insects that attach to the branches and leaves of a bonsai tree. Instead of biting or chewing leaves, scales feed on the sap from needles and stems. Heavy scale infestations bring about deformity in new growth, yellowing of leaves and even death for your prized plant.
Aphids are small, oval shaped pests that feed on the sap of plants. They can be green, black, red or white and often congregate in colonies on the undersides of leaves. Like scales, aphid infestations can cause leaf yellowing and stunted growth.
There are several ways to treat an infestation of scales or aphids.
- One is to physically remove the insects with a toothbrush or spray them off with water. This is a labor-intensive process and may not be possible if the infestation is too heavy.
- You can also use an insecticidal soap or horticultural oil to kill the insects. Be sure to follow the directions on the product carefully, as too much of either can harm your tree.
- If you have a severe infestation, you may need to resort to using a systemic insecticide. This type of chemical is absorbed by the plant and travels throughout the tree, killing any insects that feed on it. Systemic insecticides should only be used as a last resort, as they can be harmful to the environment and can also harm beneficial insects.
- Introducing other bugs that feed on scales or aphids, such as ladybugs or lacewings, can also help to control the population.
These are just a few of the ways you can treat an infestation of scales or aphids on your bonsai tree. If you think your tree might be infected, it is best to take action as soon as possible to prevent any long-term damage.

Other Insects that May Attack the Bonsai Tree
There are also other insects that may attack the bonsai tree. These include the spider mites, borers, white flies and mealy bug.
Spider Mites
Their natural habitats are the forests, but these can also be found in your bonsai garden. These are tiny arachnids that spin webs on the branches of your bonsai especially during summertime. When left untreated, these mites can cause yellowing or silvery appearance on the leaves of your bonsai.
Borers
These are the larvae of some moths and beetles. They feed on the inner bark of your bonsai tree, which can eventually girdle and kill it. This can be identified by their winding tunnels found under the bark of your bonsai.
White Flies
These are small, sap-sucking insects that can be found feeding on the leaves and stems of your bonsai. They can cause the leaves to yellow and drop prematurely.
Mealy Bug
This is a soft-bodied, sucking insect that infests the leaves and stems of your bonsai. It secretes a sticky substance that coats the leaves and stems, making it difficult for the tree to photosynthesize. Mealy bugs can be identified by their white, powdery substance that covers their bodies.
If you suspect any of these pests are infesting your bonsai, it is best to take action immediately. There are many commercially available pesticides that can be applied to your bonsai.

Conclusion
Pests can be a major problem for bonsai trees and can cause significant damage to the plant. It is important to be able to identify the symptoms of an infestation and take action right away to treat the tree. There are many different ways to treat an infestation, so find the method that works best for you and your tree.
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How to Care for a Bonsai Ficus Tree | History, Style & Tips!