What the h*** happened?

[ahosey01]

Planted two Acoelorrhaphe wrightii about two months ago.  Had a cold event shortly after, but merely a short-duration one where the yard hit about 27F.  My Bismarckia nobilis, Syagrus romanzoffiana and Copernicia alba displayed absolutely no damage whatsoever.

Fast forward to today, and I’m walking through the garden to check on my palms.  Sure enough, both of them had dead spears!! No other leaves but one died back at all.  The ground is nice and wet for them, the soil there is good and other than that one event that lasted a couple hours at most, we’ve had no other weather of significance.  What is going on!?

[96720]

I would think maybe transplant shock but don’t give up to quickly they are suckering palms so they might put out a sucker you might also want to treat them with H2O2 I have one growing in Phoenix in the coldest part of my yard and have never had a problem with the cold.

Edited January 15, 2022 by 96720
Edition

[Merlyn]

They are pretty tough to cold, Kinzyjr's sheet shows a lot of reports with no damage above about 23.  I'd guess some physical damage to the spear during shipment or planting, or maybe an opportunistic crown fungal infection.  I'd second the H2O2 dose and see if it bubbles up.  

[ahosey01]

1 hour ago, Merlyn said:

They are pretty tough to cold, Kinzyjr's sheet shows a lot of reports with no damage above about 23.  I'd guess some physical damage to the spear during shipment or planting, or maybe an opportunistic crown fungal infection.  I'd second the H2O2 dose and see if it bubbles up.  

Is it really possible to get a fungal infection in the sonoran desert during a period of no rain on only drip?

The only fungal infections ive ever known of in AZ are all when the palm crowns get hit by sprinklers.

[96720]

It definitely doesn’t look like a cold problem it looks more like some kind of fungal problem with both of them having it they may have come with it. I never like to plant palms in the fall to winter ideally plant them in the spring when they are actively growing.

[Jimhardy]

If you could turn the palm upside down, most likely you would see

a corresponding roots loss.

[Merlyn]

They are a fairly slow growing palm, so it's possible it came with some damage or fungal infection when you bought it.  It just took a while for the spear to push out far enough to be visible?  If the spear transitions back to green at the base, then I'd guess it is "growing out of it" but I'd do the H2O2 test anyway.  I had a Chamaerops Humilis doing this last spring after a couple of 28-32F frosts.  Ordinarily that wouldn't do anything to a Chamaerops, which are hardy into the teens.  But this one got a fungus and I was too busy working in the backyard to see it for a while.  A few squirts of H2O2 once a week and it's growing normally again: