Brown Spotting on Bangalow Palm

[HyperFluxM]

Hi everyone,

I bought a bangalow palm about 3 months ago. I keep it in my room which stays fairly humid and I keep it by the window which is facing north-west (I live in South Australia). I have recently potted it into a decently sized pot to make room for growth through 2022. Since I got the palm I have had a few smaller leaves dry up and die, I have been told this is natural for the smaller leaves to die off after time, is this true? I have not cut them off yet as I have also read that the palm should be allowed to do that natrually. The main issue that I am having now is brown spotting on some of the top leaves, it started off with a little bit but now there is a fair amount. When potting I added a layer of large rocks to the bottom with smaller rocks layered on top, I then filled the pot with premium potting mix (richgro seaweed premium potting mix) I also mixed in a bit of cow manure soil as I ran out of the premium potting mix. I water once a week usually by bringing it into the shower and watering it, then letting it dry for the rest of the day. Before watering i make sure that it is no longer moist on the top by sticking my finger into the topsoil. I have not used fertiliser on the palm yet. Please ask if you need any more information about the palm, any help would be greatly appreciated. 

-Patrick

Note: The photos were taken outside after repotting.

Not sure how to post an image on this site so here are links to the photos:

https://ibb.co/gdNYPJz
https://ibb.co/R9MsVzs
https://ibb.co/XxbPhGH

[Merlyn]

On 12/11/2021 at 4:28 AM, HyperFluxM said:

I bought a bangalow palm about 3 months ago. I keep it in my room which stays fairly humid and I keep it by the window which is facing north-west (I live in South Australia). I have recently potted it into a decently sized pot to make room for growth through 2022. Since I got the palm I have had a few smaller leaves dry up and die, I have been told this is natural for the smaller leaves to die off after time, is this true? I have not cut them off yet as I have also read that the palm should be allowed to do that natrually. The main issue that I am having now is brown spotting on some of the top leaves, it started off with a little bit but now there is a fair amount. When potting I added a layer of large rocks to the bottom with smaller rocks layered on top, I then filled the pot with premium potting mix (richgro seaweed premium potting mix) I also mixed in a bit of cow manure soil as I ran out of the premium potting mix. I water once a week usually by bringing it into the shower and watering it, then letting it dry for the rest of the day. Before watering i make sure that it is no longer moist on the top by sticking my finger into the topsoil. I have not used fertiliser on the palm yet.

Hi Patrick, welcome to PalmTalk!  For photos you can just drag and drop them into the text, or add them as attachments.  Sometimes you need to scale them down by 50% if they are huge files.  A lot of people (myself included) won't click on random external links due to the risk of spyware/malware/encryptionware.

Regarding your questions:

• It's common for the oldest leaves to dry up and die as the palm is growing a new spear leaf.  The general rule of thumb is don't cut off anything green, or anything below horizontal.  So an older fully brown leaf is always safe to remove.  Cutting them early can be done for cosmetic or clearance reasons, but it's better not to unless you need to.  Palms will "eat" the old fronds for nutrients, and cutting a green leaf is a potential entry point for fungi or other pathogens. 
• Palms in pots generally need a fast draining mix that doesn't stay wet for days on end.  A lot of pre-made potting mixes hold way too much moisture for palms, and tend to get "mucky" and cause root rot.  The "pros" tend to use their own mixes of soil, you can read a lot about that here:My soil mix is for mostly outdoor palms in Central Florida, I use about 30% generic topsoil (mostly finely shredded trees), 30% perlite, and 30% Turface MVP.  I add some crushed limestone for palms that want more basic soil, and increase the amount of perlite for palms that want to be really dry.  Others use pumice instead of perlite, but in Florida pumice is $50+/cuft and perlite is $8/cuft.  Turface MVP is basically pelletized fired clay and is used to retain water.  I just found a source for tiny pine bark nuggets, so I've started adding that in too.  I never use manure.

My guess, without seeing photos, is that your soil mix may be too dense and you've got a fungal infection starting.  I don't do indoor gardening, so others here may have better suggestions.  Drag and drop a couple of photos into the post and hopefully someone has some good suggestions.

[HyperFluxM]

Hi Merlyn,

Thank you for your reply, I'll look into thoes custom potting mix materials you provided. I really hope my palm doens't have a fungal infection. I just want to sort the plant out incase it gets worse and harder to heal later on. Here are the photos:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Merlyn]

On 12/15/2021 at 7:47 AM, HyperFluxM said:

The streaky spots in the above photo look like they could be sunburn.  I've had this on some palms that were suddenly exposed to more sun.  If the frond grew in a nursery under shade cloth it was used to partial shade.  Then suddenly going into full PM sun can burn fronds.  There isn't anything that can "cure" that frond, but new ones should grow out sun-adapted and won't burn.  Archontophoenix Cunninghamiana (Bangalow Palm) is known as being somewhat sun-tender when they are young.  You could move it back from the edge so it gets a little bit less direct PM sun, but it should adapt.

[HyperFluxM]

That does make sense as ive had it back inside for about a week now and have not noticed any extra streaky spots. Ive got it by the window which is just above the plant so it should be more comfortable now. Im glad to hear that it should adapt, that'll relieve some stress lol. Thankyou very much for all your help. 

[D Palm]

I planted mine in a full blown Florida sun location this summer.  About 60% of the fronds were burned. I believe this palm is more prone to sun burning at the juvenile stages. Probably not a fungus.

[Merlyn]

On 12/17/2021 at 11:03 PM, D Palm said:

I planted mine in a full blown Florida sun location this summer.  About 60% of the fronds were burned. I believe this palm is more prone to sun burning at the juvenile stages. Probably not a fungus.

I had the same problem with planting a few seedling+ sized Kings.  At about 1-2' tall they just burned to a crisp in full sun, even in my 'tropical bed" that gets drenched every morning.  If they had some PM shade (I used a random Dwarf Cavendish just to the West side) they greened back up and adjusted with the next new fronds.  I'm going to take out the Cavendish in the spring and see if they have adapted.  I figure that I'll use the Cavendish as a sacrificial frost shelter this winter, it'll absorb at least one good frost and spare the 2 footer from the brunt of the cold.  

[D Palm]

11 hours ago, Merlyn said:

I had the same problem with planting a few seedling+ sized Kings.  At about 1-2' tall they just burned to a crisp in full sun, even in my 'tropical bed" that gets drenched every morning.  If they had some PM shade (I used a random Dwarf Cavendish just to the West side) they greened back up and adjusted with the next new fronds.  I'm going to take out the Cavendish in the spring and see if they have adapted.  I figure that I'll use the Cavendish as a sacrificial frost shelter this winter, it'll absorb at least one good frost and spare the 2 footer from the brunt of the cold.  

I had a dwarf cavendish developing fruit and the frost took it to the ground last year. Super messy and disgusting, I dug up what was left and burnt it. 2-3 mid 30’s heavy frost and my king hasn’t flinched…that was a few weeks ago. It even pushed out a new frond since…