Frangipani rust is a fungus that often pops up around December and needs to be controlled by spraying a fungicide. It’s impossible for a frangipani nursery to avoid getting rust and most likely impossible to eliminate it. To make the situation more challenging, frangipanis in pots and bags aren’t usually as strong as those in the ground and are more vulnerable to all pests and diseases.
The good news for landscapers and home owners is that with only a few frangipanis or less, rust can be treated easily and elimination is possible. If you plan to put your frangipani in the ground, treatment will be even more effective.
It’s common knowledge that rust does not harm the frangipani however if the rust is left untreated from early Summer through to winter, all the leaves will eventually turn brown and fall off earlier than usual. From my experience, frangipanis that are badly infected with rust not only look bad but look unhealthy and weaker so it’s best to treat it sooner than later.
We look for areas in our nursery that have rust and spray as soon as possible. After spraying, the rust turns white (attacked by a good fungus?) or turns black (dead rust?) which ends up giving the leaves black spots. Leaves deteriorate during this process and turn yellow, then brown and eventually fall off. This is unavoidable but if the rust is sprayed well, the new leaves will look healthy and will remain rust free for longer.
Sometimes we can’t spray for 2 or 3 weeks due to rain or other reasons and the rust gets really bad in some sections of the nursery. Sometimes, we focus on spraying some sections while rust spreads without anyone seeing in another section.
The more the rust spreads, the more it creates so it’s in our best interest to minimize it as much as possible however eliminating rust in our whole nursery AND preventing it from entering the nursery after that is impossible.
We have found if we spray twice in 2 weeks, 99 percent of trees will be rust free a week later. In addition to that, we make sure that any frangipani with rust leaving the nursery is sprayed in the week leading up to departure. While we can easily improve the appearance of a frangipani by cutting blemished leaves off and hole the rust off by spraying, rust likes to come back and spread. We suggest that every frangipani owner learns to identify rust quickly and learns how to treat it.
Mancozeb is a fungicide that can be bought at Bunnings for around $10 and is enough to last for years.
Almost all customers who own or have owned frangipanis are familiar with rust and understand this but customers are welcome to ask us about rust in general or rust on a specific frangipani before ordering it online.
For a more detailed description of frangipani rust and how to treat it, please see our other blog post. What is frangipani rust?