Bismarckia help

[Castro210]

I planted this in September of 2018 out of a 25 gallon pot. Since then it has grown at a pretty aggressive rate. I would guess in the 2 years it’s went from right at 5’ tall to about 13’ tall. 
 

in the past month or two I’ve noticed some slight yellow streaks in the leaves. It’s overall turned a little more green than its perfect silver start. This last week I’ve noticed some brown dead spots as well. 
 

I gave it would I guess to be 4 lbs of Palm special in August and due to our very fast drainage fertilize every 3-4 months. I gave it some iron earlier in the week to see if that would help too. 
 

any ideas of what could be happening or concerns about the tree would be appreciated.

[sonoranfans]

Bismarckia are not in need of much fertilizer they grow in micronutrient depleted lateritic soils on madagascars high plains(6500' elevation if I recall correctly).  I'm not sure Key west, perfect for many palms, is perfect for bismarckia.  They like heat and longer dry cycles for the roots.  I lost a 25 footer that saw too much water in a really wet year, it was in the runoff drainage path but it was high drainage soil.  I still have a 30 footer that is doing great, but its not in the drainage path.  These palms like to grow really deep roots, more than 4' deep, in my experience and you should get some dry cycling down there to ensure healthy roots.  I have had 7 bismarckias in 2 gardens, never saw a nutrient deficient one.  

[PalmatierMeg]

Are new leaves affected or just older ones? One of your photos shows a leaf that looks brownish and dessicated. Do others look like that? Are any stunted or drooping?

I'm not trying to alarm you but does your area have a problem with palm weevils, which normally plague Sabals, that attack Bismarckias? Here in Cape Coral we had a number of Bizzies destroyed by weevils that developed a taste for them. One of those Bizzies was my oldest and largest. Over the course of a year it looked increasingly sickly until one day the whole crown collapsed. The poor thing was infested with grubs & adult weevils. We had to cut it up and send the remains out with the trash to be incinerated.

https://www.palmtalk.org/forum/index.php?/topic/47332-largest-bizzie-destroyed-by-palm-weevil/&tab=comments#comment-726535

I hope I am wrong but I suggest you examine the crown and meristem area of your palm for bore holes and debris

[Jerry@TreeZoo]

Key West?  Any salt water intrusion?

[Castro210]

Thanks for all of the replies. I’m about 7’ above sea level. I have another Bismarck on the canal in the back yard that is perfect. There are many of these all over my canal neighborhood and much of them lower elevation. I don’t think that’s a problem. 
 

The emerging 4 spears are very healthy looking. The 3-4 newest open leaves are perfect. It’s only below that where there is any discoloring.  
 

I’m not sure anything major is wrong. I am just trying to stay ahead of it just in case. This tree has gotten a lot of wind with all the tropical weather over the past couple months so that hasn’t helped. 
 

I’ve looked it over and can’t see anything abnormal outside the discoloring of the older leaves mentioned initially. 

[SouthFLA]

Use slow release 8-2-12 palm fertilizer, problem solved. Classic nutrient deficiency symptoms in your photo.