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Eugenia Plant Problems — 6 Things to Know

Eugenia Plant Problems — 6 Things to Know

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I love my eugenia plants. I planted mine near my white-picket-fence to make my front garden area more private. I also own a few that I use for topiaries too.

I ensure I take really good care of my eugenias since they are my pride and joy, and the second thing anyone who passes by my property will notice. The first being my lovely cottage, of course!

One morning, however, I went to water my eugenias, only to find that they’d been infested with disease and pests. How could I fix this and get my eugenias thriving again?

I realized I needed to learn about the common plant problems that can plague eugenias, and you’ll learn all I discovered in this in-depth guide.


Eugenia Plant Problems

Insects in the form of psyllids; whiteflies; armored scales like Florida red scales and Oriental scales; soft scales like mealybugs, brown soft scales, and black scales; aphids, black spider mites, and slugs and snails can affect Eugenias. Fungal diseases, like rust, fungal leaf spot, and dieback also affect this plant as well. 


Common Plant Problems With Eugenias

There are a few plant problems eugenias, also called Australian brush cherry or Syzygium, can experience.

I’ve had a few of these problems with my eugenias, so I want to make it easy for you to diagnose what could be wrong with your evergreen shrub.


Plant Problem 1: Eugenia Psyllids

A psyllid is a sap-sucking insect that commonly plagues eugenias. These insects have dark-brown bodies and a white band around their abdomen.

They are tiny, measuring one-fifth to one-tenth of an inch. Psyllids lay eggs that are golden in color on the leaf edges.

When psyllids are still in their crawler stage, they look like scale insects and feed on the leaf. When my eugenia was infested with psyllids, there were reddish areas on the leaf where these insects fed on the juices of the plant.

I once had a high population of psyllids, which negatively affected my plants’ growth. The foliage was also discolored.

Having ladybugs in my garden has helped keep the psyllid population under control. I also sometimes need to take more extreme measures so I mix a gallon of water with 2 tablespoons of neem oil.

I then spray this organic insecticide weekly on the top and underside of my eugenia’s foliage.


Plant Problem 2: Rust

Rust is a fungal infection that affects eugenia plants. When my shrubs were infected, I found puffy and orange rust on the underside of the plant leaves.

The spores travel by water and wind, and as such, it is easy for this infection to spread from one eugenia to the next.

I’ve found that rust germinates when it is hot and the level of humidity is high. The only way to get rid of this fungal infection is by using systemic fungicides to prevent the spores from germinating.


Plant Problem 3: Other Insects

Apart from psyllids, there are other sap-sucking insects, like whiteflies, scales such as armored scales and soft scales, aphids, and red spider mites. All of these insects also feed on the plant’s juices.

While there are a variety of scale insects, they appeared as small bumps on my eugenia. These insects are either stationary or move.

Armored scales are from the Diaspidadae family, and the species that cause the most damage to my eugenias are Oriental scales and Florida red scales. These scales are plate-like at about 1/8 of an inch in diameter.

Soft scales are a bit bigger at a quarter of an inch, and these insects are smooth, waxy, or cottony.

These scales excrete honeydew, which is like sugary water that attracts ants, and this leads to mold growth that is similar to soot in appearance.

Black scales, mealybugs, and brown soft scales are examples of soft scale insects that make eugenias their home.

Whiteflies are moth-like insects that are white and tiny. They are not a serious threat to the Australian brush cherry and an easy fix is having more ladybugs around to keep the population of whiteflies under control.

To get rid of sap-sucking insects, I spray my eugenia bush with insecticidal soap, like the mixture I use with psyllids.

Alternatively, I also mix 1 gallon of water with 5 tablespoons of insecticidal soap that I get from my local nursery.


Plant Problem 4: Fungal Leaf Spot

Fungal leaf spot infections occur when the eugenia leaves stay moist for an extended period. Lesions start to develop on the leaf and the edges look worn as it turns dry.

I control fungal leaf spot by ensuring my eugenia’s foliage is never moist. I ensure that the branches don’t overlap by pruning regularly.

I also remove any leaves that are infected. If the problem persists, I resort to chemical sprays to help me get rid of this fungal infection.


Plant Problem 5: Eugenia Dieback

When the branches of my eugenia defoliate and wilt, I know that my plant has been infected by a fungus called Neofusicoccum parvum, which causes dieback. This disease is common when the temperatures are high during summer.

To eliminate dieback, I prune the infected branches and apply a fungicide. I cover every surface of the plant to be safe and I ensure my plant isn’t stressed, as a non-stressed plant helps prevent this disease from taking root.


Plant Problem 6: Snails and Slugs

A few years ago, I found many snails and slugs feasting on decaying plant matter around my eugenias.

Both of these insects have the potential to lay eggs, and they chew irregular holes in plant leaves, flowers, and other succulent plant parts like the young plant bark and fruit.

To get rid of these pests, I regularly remove all dead plant matter and hidey spots where these creatures take shelter during the day.


Frequently Asked Questions about Eugenia Plant Problems


How do I get rid of Eugenia psyllids?

Before treating your eugenia, check and make sure that the psyllids are still feeding off the plant. If they are still there, you can spray your eugenia weekly with insecticidal soap or neem oil. Don’t prune the plant to get rid of these insects as the psyllids easily jump away, onto their next feeding ground.


What is an insecticidal soap for plants?

Insecticidal soaps are used to get rid of harmful plant insects, like thrips, aphids, whiteflies, mites, and immature leafhoppers. Using an insecticidal soap is an eco-friendly way to effectively dissolve the exoskeleton of the insects (due to the fatty acids in the soap), which then dehydrates the insects and causes them to die.


The Final Word

Eugenias can be plagued by many plant pests and fungal diseases. Knowing what could be wrong with your shrub helps you diagnose the issue and eliminate the insects or fungal disease.

Luckily, getting rid of plant problems isn’t too challenging as you should ensure there are a significant number of ladybugs in your garden, regularly prune branches and especially if any are infected, and spray an insecticide or fungicide.

Good luck!