Queen Palm Crown Rot Solutions?

[Sarah Mehringer]

I am in the Phoenix metro area and this summer I noticed I was losing the center frond (as it was still growing) it's been exceptionally hot, so I assumed they needed more water 🤦‍♀️ now I'm learning that there's such a thing as Crown Rot 😭 sure enough I pulled the leftover pieces of dead frond and they are black and moldy. Can anyone please direct me to a good fungicide? I'm also learning there are different types of Queen Palm... please don't ask me which type mine are.... any help would be greatly appreciated. We spent a small fortune on these and have been babying them for 3 years.... I'm desperate to keep them alive.... 

[Harry’s Palms]

Syagrus Romanzoffiana , like other palms are variable but there is only one type. There are hybrids but yours appears to be the Queen palm not a hybrid. If the crown got wet due to overhead watering or rain then combined with heat from Arizona summer , then the crown can rot. I have never had that in the 30 years I’ve been growing them but they are weeds here in Southern California. Some folks here use hydrogen peroxide down in where the spear was and you should see bubbling or foam . Then there is a procedure used to try to cure the damage , again I’m unfamiliar so wait for someone who has done this to give more sage advice. Yes , Queens grow in some parts of Arizona but not sure if they are happy in your area. Harry

[SeanK]

Sorry to see you have problems with these. Not sure why "a small fortune" as Queen palms are practically a weed, second only to W.robusta.

Please get a better, daylight photograph. You will need a ladder to administer H2O2 or Daconil. I can't say if cutting is necessary.

I suggest palms that are more appropriate for the climate you're in. Queens are water lovers. Better to have Pigmy Dates which are easier to protect below 25°

[Merlyn]

@Sarah Mehringer a good daytime photo would help!  As others mentioned, crown infections are somewhat common and can be treated.  My favorite is hydrogen peroxide followed by Daconil at least 10 minutes later.  H2O2 is a powerful antifungal for people as well as palms, and it bubbles up in the presence of fungi.  So it's a good diagnostic to know that there's still fungus present.  And it's cheap!  Most of the palms I've treated have been fairly small, so a good squirt is plenty.  For one that size I'd douse it with about 8oz of H2O2 and then a Daconil mix about 10 minutes later after the reaction is complete.  Repeat 2x to 3x per week until the H2O2 no longer bubbles up.

Other treatments that people recommend here (but I haven't tried yet) are a copper-based solution and Mancozeb.  Copper is phytotoxic when used repeatedly, but very effective.  Mancozeb was recommended to me by a local grower as the best he's tried.  I've bought it but not used it yet.  Banrot, Fosetyl-Al (or Aliette, or any aluminum tris), Phosphite, Mefenoxam and Propiconazole are systemic fungicides recommended by UFL for treatment.  I've used Banrot and Fosetyl-Al for systemic treatment of fungal infections on palms, though not specifically for Phytophthora bud rot.

Here's a fact sheet on it from UFL: https://edis.ifas.ufl.edu/publication/PP144

[Sarah Mehringer]

Thank you everyone! I'm heading to the store now! I really appreciate all your advice! I'll post a day time photo when I'm up on that ladder! 

[MJSanDiego]

6 hours ago, SeanK said:

Not sure why "a small fortune" as Queen palms are practically a weed, second only to W.robusta.

Haha so you have alot of queens and robusta in Atlanta? 😳 Syagrus romanzoffiana is one of the most gorgeous pinnate palms when planted in appropriate climates, which is why they are readily available and ubiquitous here. Due to abundance they are often sold and planted in areas where they should not be. You can't plant a King palm in the desert for example. The Queen is more adaptable to the deserts to some extent, but within limits though, because its not even close to its native habitat

[MJSanDiego]

People always blame the palm giving Syagrus Romanzoffiana a bad name. It's not the palm's fault. Its the people. Planting in the wrong places. Many are even upset with Queens in Florida that do not look well. There is a recent thread here on this. They dont like much of Florida's native soil and people are also trying to plant too far north, like north of Clermont. Now they classify it as invasive. Not the palms fault....

[SeanK]

5 hours ago, MJSanDiego said:

People always blame the palm giving Syagrus Romanzoffiana a bad name. It's not the palm's fault. Its the people. Planting in the wrong places. Many are even upset with Queens in Florida that do not look well. There is a recent thread here on this. They dont like much of Florida's native soil and people are also trying to plant too far north, like north of Clermont. Now they classify it as invasive. Not the palms fault....

Yes, I know you love Queen Palms. I don't hold it against you.

[MJSanDiego]

18 hours ago, SeanK said:

Yes, I know you love Queen Palms. I don't hold it against you.

Yep, you know me by now! I love dark green feathery pinnate graceful stately tropical elegant palms, a.k.a Syagrus Romanzoffiana

[Sarah Mehringer]

Thank you to everyone who helped with this problem. I've now treated my palms 2 times in a week, with both hydrogen peroxide as well as the liquid copper. I cut out what I could of the infected fronds, although there's still a significant portion left down in the crown of the tree.

I'm wondering if you have any idea how many times these will need to be treated and if it is working, how long do you suppose it will be before I can see health returning to them? 

My thought was they may need to be treated each time it rains for a while, which during monsoon season in Arizona, will be fairly frequently over the next couple months. 

My next question is, is there some kind of preventative care I can do that will prohibit this recurring?? 

Also attaching daylight photos, sorry that took so long, it's dark by 7pm and I'm generally doing this after that.... 

 

[Palmfarmer]

On 8/29/2024 at 5:47 AM, SeanK said:

Sorry to see you have problems with these. Not sure why "a small fortune" as Queen palms are practically a weed, second only to W.robusta.

Please get a better, daylight photograph. You will need a ladder to administer H2O2 or Daconil. I can't say if cutting is necessary.

I suggest palms that are more appropriate for the climate you're in. Queens are water lovers. Better to have Pigmy Dates which are easier to protect below 25°

Why would he have to protect it? He lives Phoenix which is 10A more or less right?. Queens can take a lot of cold especially in dry climates.

He could put a Bismarck in its Place. They do well in Deserts with some additional water. If on a budget He could get a Filifera perhaps

[Merlyn]

@Sarah Mehringer a couple of comments:

• I'd limit the use of copper to one or two doses.  In frequent use it's phytotoxic, i.e. it'll kill your palm.  Using it daily or semi-daily is probably a bad idea. 
• I would leave the infected spear in place and mark it horizontally with a sharpie against fronds next to it.  That way you can see if it's actively growing upwards.  This is an easy way to see if the crown is damaged or dead.  If it's just damaged then the spear will slowly grow upwards, even if it looks ugly.  If the spear is in there solid but *not* moving then the growing point might be dead.  The good news is that many palms will recover from "spear pull," where you can easily pull a rotten spear out, and a few weeks to a month or so later it'll push out a new one.
• I'm not sure about this one, but maybe snip a few of the brown fibers that are holding the crown tightly together?  This could open up the crown and allow better airflow.  But it might also remove some support for existing fronds and make it more susceptible to wind damage. 
• I'd buy a bottle of Daconil and do that after the 2-3x per week hydrogen peroxide.  Daconil is kind of sticky, so it sits in place for days on the surface. 

It might be several weeks before you see a hint of a new spear sticking out.  If you stop seeing bubbling with the hydrogen peroxide then the fungus is probably killed off.  The only thing you can do at that point is hope it grows another spear!