I'm afraid I'm not too familiar with diseases or pests of Eugenias. In fact there are not that many major diseases of this plant. I would take it back to the nursery right away to at least have it assessed. It's possible that it was already diseased when you bought it. Your plant is also known as an Australian Brush Cherry, in case you'd like to try to research more on it.

I'd also advise you to contact the tropical forum and the pests and diseases forum for their thougts on this.

Ianna

Hi,
Sorry to hear about your spiral, I believe what you are describing is called Florida brown scale or black scale I can't rem. for sure, I believe the scale is sucking juices from the plant, causing the upper portion to die back, or it is allowing a secondary infection to enter through the wound, you can spray with a citrus oil to smother the scale but be careful because in the summer months its easy to burn with oil, also; maybe a safer soap would be worth a try.(I use Sygon, but you may not be able to get it)
It may also be a stem blight which causes dieback in eugenia in which case you need a systemic fungicide to cure the plant, if you do this, cut off the damaged part and throw it in the garbage to get it out of your yard, then you can begin to retrim the spiral with the new growth.
Finally; the eugenia usually do great in full sun but seem to get leggy and sutty mold in full or partial shade.
Sorry to be so wordy, I just wanted to share my experiences with this plant, also the plant really grows fast this time of year so you might consider low nit. fert. and Ironite, or just ironite granular I've never burned with it and it keeps the eugenia dark green.
ps. trim often so you don't lose the shape,and forgive any spelling or grammer errors.
Good Luck,
Gene

I am an entomologist in Boca Raton, FL. Although I really work with ants, I have seen Eugenia with these insects all over Broward and Palm Beach counties, and ants feed on the honeydew produced by these scale insects. The Eugenia plants look like they were hit by a flame-thrower. As I said, the scales produce honeydew which they excrete and then sooty mold (black) grows on the honeydew. I asked my friend who works with scale insects about this. He says that this is the work of the Florida Wax Scale, Ceroplastes (he does not know which species). The family is Coccidae. I can email photos if anyone wants to see them. Maybe I will post them on my website.

Many people have asked me what they should do about this. I have seen Eugenia dying all over and, really, if you want to spend time fighting this, you will probably have to keep spraying the plants with a systemic insecticide like Merit continually, and even then, it might be an uphill battle all the way. Usually in a case like this with a well-established insect pest, the best thing to do is to plant resistant varieties, or some other ornamental plant. I don't know if there is a Eugenia variety that is resistant to this wax scale, maybe someone on this forum knows.

John Warner, PhD qualified entomologist
University of Florida
Fort Lauderdale Research and Education Center, Ant Lab
3205 College Avenue
Fort Lauderdale, FL 33314
USA

Here's a photo of Ceroplastes (Florida Wax Scale) on Eugenia (see link below). The black on the leaves is sooty mold.

-John

Here is a link that might be useful:

We have tress with the FLorida Wax Scale and are thinking this tree is too far gone to attempt to save. With this disease is it possible to replant another or is the soil contaminated also.

The best spray that i have used is a combination of
Daconil ultrex and Heritage.The rate is 1 LB. Daconil
and 2 ounces Heritage per 100 gallons. Also some soaps or
oils have helped to slow this disease.

I have seen many (most?) Eugenia plants with Florida Wax Scale in Palm Beach and Broward Counties. My suggestion is to not try and save them. To save them would probably mean treating them every 2 weeks with an insecticide. In cases like these where you have a difficult-to-treat scale insect, usually the best way to go is to plant something that is resistant to the scale.