What is this on my King Palm?

[Hoochtastic]

Hello,

I planted a triple King Palm about three months ago in Southern California. I fertilized it when planted and it's getting lots of water. However, groups of black spots are growing on two of the stalks that look like fungus or mold. Does anyone know what this is and how I can get rid of it?

The second photo shows the full tree and the spots are about halfway up the left stalk.

Cheers!

[MJSanDiego]

Hello and welcome to the forum! This might be sunburn from the recent heatwave from prior weeks.  King palms need time to acclimate to full sun as nurseries usually grow in shade. So you might see burn on the old fronds too. But new growth will emerge and will adjust to the sun. However, this could also be caused by fertilizing when planting which is not recommended and can burn the plant. If it's not a growth and smooth, I lean towards sunburn or fertilizer burn. If it is a growth like mold or fungus it would need fungicide.  But at this time I say it's sunburn and not an immediate concern but definitely keep an eye on it and see if it progresses

[Harry’s Palms]

It certainly could be sunburn and or getting ready to shed leaf base. Harry

[Tracy]

6 hours ago, Hoochtastic said:

Hello,

I planted a triple King Palm about three months ago in Southern California. I fertilized it when planted and it's getting lots of water. However, groups of black spots are growing on two of the stalks that look like fungus or mold. Does anyone know what this is and how I can get rid of it?

The second photo shows the full tree and the spots are about halfway up the left stalk.

Cheers!

I am looking at the surrounding area to your palm which appears quite dry.  I don't know where in California you are located but thought it worth mentioning that these appreciate a lot of water.   That is directly correlated to your climate and soul's ability to retain the water.  While you have mulched an island around your palms additional low plantings might help reduce evaporative water loss inside the ring.

The brown spots could be related to transplant shock or just sunburn.  Autumn has officially arrived today so one thing is for sure,  the sun's intensity is decreasing.  The new challenges you will face in winter all depends on where in California you are located. 

[Hoochtastic]

I appreciate the replies. The black spot is smooth, and does not penetrate through to the next layer when you pull back the husk, so it's probably just sunburn. I'll keep an eye on it.

Regarding water, I'm located in Ventura, CA about a mile from the ocean. The tree is getting ~6 gallons of water a day through 4 emitters in a ring around the tree with wood chips on top to retain moisture. The ground underneath the chips is always soaked. I read that it's nearly impossible to overwater King Palms, but is that still too much water?

[MJSanDiego]

1 hour ago, Hoochtastic said:

I appreciate the replies. The black spot is smooth, and does not penetrate through to the next layer when you pull back the husk, so it's probably just sunburn. I'll keep an eye on it.

Regarding water, I'm located in Ventura, CA about a mile from the ocean. The tree is getting ~6 gallons of water a day through 4 emitters in a ring around the tree with wood chips on top to retain moisture. The ground underneath the chips is always soaked. I read that it's nearly impossible to overwater King Palms, but is that still too much water?

Many will state that you can't overwater a King palm and they grow in standing water but that is a blanket statement. If grown in a nursery pot in nice sandy potting soil and then transplanted into the ground in clay you can overwater it and get root rot. That happened to me in clay soil. It really depends on your soil and drainage. If you have clay like me, I would check on how wet it is below. But if you have loam or sandy I don't think you can overwater it 

 

[Hoochtastic]

Got it, our soil is dense clay and the days are getting a little cooler and foggier. I reduced the water to ~4 gallons a day and may take off most of the wood chips. I would hate to lose the tree to root rot.

Cheers

[MJSanDiego]

Yep just use your best judgement. You have to be careful not to underwater abruptly either. If it's warm especially, the soil is still warm this time of year, even the clay. But during the cooler weather during rainy season and in clay is where you can run into trouble especially until it gets acclimated.  You also want to make sure to water the immediate root ball at the trunk base as many roots may not have penetrated far into the clay yet in 3 months time, depending. The sandy original potting soil from the nursery pot dries out quickly. Hope that helps

[Jim in Los Altos]

3 hours ago, Hoochtastic said:

Got it, our soil is dense clay and the days are getting a little cooler and foggier. I reduced the water to ~4 gallons a day and may take off most of the wood chips. I would hate to lose the tree to root rot.

Cheers

King palms are semi-aquatic. They will grow happily and robustly in saturated soil and even IN water. I have some that are growing in stagnant water 365 days per year and they love it. My other 50 King palms are in more conventional conditions but still get lots of water and often. Remember also that their roots travel horizontally many yards so don’t just water at the palm’s base. 
 

[DoomsDave]

@Hoochtastic nice to meet you!

I concur with everyone about everything said on this thread and note that kings are swamp things. 
 

Mucho agua! Treat them right and they’ll delight.

These are close relatives after about 15 years in the ground.

[DoomsDave]

On 9/22/2024 at 5:44 PM, Jim in Los Altos said:

King palms are semi-aquatic. They will grow happily and robustly in saturated soil and even IN water. I have some that are growing in stagnant water 365 days per year and they love it. My other 50 King palms are in more conventional conditions but still get lots of water and often. Remember also that their roots travel horizontally many yards so don’t just water at the palm’s base. 
 

50 kings plus how many more?

Bet your place is a landmark up north.

[Jim in Los Altos]

4 hours ago, DoomsDave said:

50 kings plus how many more?

Bet your place is a landmark up north.

Dave, I’m including A. alexandrae, purpurea, and myolensis along with the cunninghamiana and ‘Illawara.’ Will add a maxima when I find one. 🙂

 

[DoomsDave]

6 hours ago, Jim in Los Altos said:

Dave, I’m including A. alexandrae, purpurea, and myolensis along with the cunninghamiana and ‘Illawara.’ Will add a maxima when I find one. 🙂

 

Come down south for a visit! I have some! Maximas and tuckeri.