I think my huge Sylvester Palm is dying

[Tiff]

I live in north central Florida and have a huge 20 year old Sylvester Palm in the middle of my drive way.  I've only lived here for 1 year and moved here from Utah and have no knowledge of palms. In the year i have lived here I've never seen this Palm look this bad. Please help me save this gorgeous palm!

It has its own sprinkler but we have a smart sprinkler timer system that won't go if it rains. We are getting almost daily thunderstorms right now. It has good drainage as it is situated on high ground. There is a bulge in the trunk (see pic) that doesn't look great- the outside bark is being pushed out.

[SeanK]

IMHO, it looks like lethal bronzing.

I hope I'm wrong. Some Floridians can chime in as PHX palms are common in the central part of the state.

[Merlyn]

@Tiff the lower roots are not a concern, Phoenix palms frequently grow "adventitious roots" waaaay up the trunk.  There's a Sylvestris near me with roots coming out at least 7 feet up the trunk. 

The browning of the lower fronds is more concerning, but could be just a Magnesium deficiency.  I'd add some Magnesium Sulfate asap, in addition to maybe 2lb of a good "palm" type fertilizer.  The common recommendation here is PalmGain or Florikan.  I usually use Sunniland Palm 6-1-8. 

As @SeanK mentioned, the other concern is Lethal Bronzing.  This is an incurable phytoplasma disease that is wiping out Sylvesters across FL.  *IF* the lower fronds are browning rapidly and the new spear leaves are flopping over sideways, then it's likely infected and should be removed.  *IF* they have just slowly been getting worse it may just be Magnesium.  Here's a fact sheet on LB:

https://edis.ifas.ufl.edu/publication/PP163

[Tiff]

@Merlyn and @SeanK I live close to UF so I am going to call them tomorrow about the Lethal bronzing. I found some epsom salts and am watching YouTube videos on how to apply. Then I will get my hands on some fertilizer. We have not treated this tree at all since we have lived here so I am praying it is just a magnesium deficiency - and now we know we need to feed it. Thank you so much for your responses.

[Fusca]

  On 8/18/2024 at 9:12 PM, Tiff said:

@Merlyn and @SeanK I live close to UF so I am going to call them tomorrow about the Lethal bronzing. I found some epsom salts and am watching YouTube videos on how to apply. Then I will get my hands on some fertilizer. We have not treated this tree at all since we have lived here so I am praying it is just a magnesium deficiency - and now we know we need to feed it. Thank you so much for your responses.

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Hopefully it's just the magnesium deficiency!  Keep in mind that the fertilizer won't fix the discolored fronds but will ensure that the new growth in the center of the crown will emerge healthier.

[Merlyn]

@Tiff I bought a big 25lb bag of Magnesium Sulfate from HD, I think.  I use 2 big handfuls of the granular, sprinkled around the base going out several feet.  Manganese deficiency looks different, it shows up on the new fronds.  If it's a Manganese problem then the palm should stop "eating" the older fronds in a month or so.

[Merlyn]

  On 8/18/2024 at 10:20 PM, Merlyn said:

@Tiff I bought a big 25lb bag of Magnesium Sulfate from HD, I think.  I use 2 big handfuls of the granular, sprinkled around the base going out several feet.  Manganese deficiency looks different, it shows up on the new fronds.  If it's a Manganese problem then the palm should stop "eating" the older fronds in a month or so.

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Whups, I was way too tired when I typed this.  To clarify:

• Magnesium is "mobile" in plant tissues, so if the palm is short on Magnesium it will steal it from the oldest fronds.  They will turn yellow then brown.  Extra supplemental Magnesium will reduce the "eating" of older fronds.  For a big Sylvester 2 handfuls of Magnesium Sulfate granular (in addition to a normal "palm" type fertilizer) seems to work for mine.
• Manganese is NOT mobile in plant tissue, so if a palm is short on Manganese it will show up in the newest fronds as they grow out.  This is sometimes called "frizzle top."  I have had this on Cycas Revoluta (sago) and 1 handful of Manganese Sulfate with a "palm" type fertilizer fixes it for the next flush.  I haven't had this on any palms.

[SeanK]

Doesn't Mn deficiency show up as frizzle top?

[Looking Glass]

Manganese deficiency will show in the new leaves. It can be yellow streaks, necrotic streaks, or frizzle top.   

 

Magnesium deficiency shows up in the oldest leaves,  it will cause yellowing at the margins.   It isn’t fatal, and doesn’t cause leaf tip necrosis/browning by itself.  

 

Concomitant potassium deficiency is common with magnesium deficiency and will cause necrosis/browning on oldest leaflet borders and is eventually fatal to palms over a long period of time.

 

These two deficiencies are common in Florida in Phoenix family palms.   For this reason, it’s a good idea to treat with langbeinite/Sul-po-mag or to balance your potassium or magnesium supplementation by adding both.   Mg and K are antagonistic to each other so it’s best to add both.  

What they look like: https://discover.pbcgov.org/coextension/horticulture/pdf/commercial/Nutrient Deficiencies of Landscape and Fieldgrown Palms in Florida.pdf
How to fix deficiencies :
https://www.palmbeachpalmcycadsociety.com/documents/PalmNutritionalDeficiencyCorrectionAndAntagonisticNutritionalRelationships.pdf

Lethal bronzing should cause death of the fronds from oldest up, and eventually the palm over 4-5 months. 
https://www.westonfl.org/government/landscaping/safeguarding-your-landscape-from-pests/lethal-bronzing-disease-lbd