MEXICAN FAN PALM SEVERE FIRE ANT INFESTATION

[TexasPalmPeople]

MEXICAN FAN PALM SEVERE FIRE ANT INFESTATION
This Mexican Fan Palm (Washingtonia robusta) is about 12 years old, and stands about 18-20 feet at the crown - located in northwest Houston, Texas.

This past week, I noticed fire ants on the trunk and removed some loose bark. Armies of fire ants poured out. Yesterday, I probed the debarked areas - and this palm seemed severely damaged (soft, dead tissue) to a depth of about 1.5-to-2" on for at least half the circumference of the palm, from a height of 10" above the ground up to 3'-to-4' above the ground. I have not removed bark from the full circumference of the palm, however tapping the bark with the side a long screwdriver, it sounds 'hollow' for the balance of the circumference; consequently, I believe the condition represented by the photo continues around the whole palm for the same height. I have just treated the ants to kill them, but would appreciate opinions on the potential for the palm to survive this damage. I would hate to remove this palm if we don't have to.

Additional info: we bought the house eight years ago, which included five young Mexican Fan Palms. This palm, and one other, survived three very hard freezes in the past five years: one in which temperatures dropped to 17° overnight, and one other a year later with an overnight low of 11°;  and another where the temperature stayed below freezing for five days - with temperatures in the mid-20s during the day, and night temperatures in the the low 20s and upper teens each night. Three Mexican Fan Palms died during these freezes. One other palm survived, and it appears to have no damage or insect infestations; that palm has a very thick trunk, and has always been robust. This palm, with the ant damage, was always the 'runt' of the five - thinner, and with fewer fronds.

Does this situation look salvageable, or should we remove it?

Any opinions or suggestions would be greatly appreciated. Thank you very much.

[MarcusH]

2 hours ago, TexasPalmPeople said:

MEXICAN FAN PALM SEVERE FIRE ANT INFESTATION
This Mexican Fan Palm (Washingtonia robusta) is about 12 years old, and stands about 18-20 feet at the crown - located in northwest Houston, Texas.

This past week, I noticed fire ants on the trunk and removed some loose bark. Armies of fire ants poured out. Yesterday, I probed the debarked areas - and this palm seemed severely damaged (soft, dead tissue) to a depth of about 1.5-to-2" on for at least half the circumference of the palm, from a height of 10" above the ground up to 3'-to-4' above the ground. I have not removed bark from the full circumference of the palm, however tapping the bark with the side a long screwdriver, it sounds 'hollow' for the balance of the circumference; consequently, I believe the condition represented by the photo continues around the whole palm for the same height. I have just treated the ants to kill them, but would appreciate opinions on the potential for the palm to survive this damage. I would hate to remove this palm if we don't have to.

Additional info: we bought the house eight years ago, which included five young Mexican Fan Palms. This palm, and one other, survived three very hard freezes in the past five years: one in which temperatures dropped to 17° overnight, and one other a year later with an overnight low of 11°;  and another where the temperature stayed below freezing for five days - with temperatures in the mid-20s during the day, and night temperatures in the the low 20s and upper teens each night. Three Mexican Fan Palms died during these freezes. One other palm survived, and it appears to have no damage or insect infestations; that palm has a very thick trunk, and has always been robust. This palm, with the ant damage, was always the 'runt' of the five - thinner, and with fewer fronds.

Does this situation look salvageable, or should we remove it?

Any opinions or suggestions would be greatly appreciated. Thank you very much.

I don't have the answer for your ant problem I'm also hesitate to recommend any chemical treatment since your palm has an open wound but others should chime in on that particular problem.  

As for the trunk goes I would like to know how severely the trunk is damaged.  Remember all the heavy weight that sits on the damaged trunk part.  It's not very uncommon that palm trees collapse from severe trunk damage,  even caused fatalities in some rare cases.  Take a screw driver clean out all dead tissue then evaluate the damage from there .

[TexasPalmPeople]

Much thanks, Marcus. It will take more than a screwdriver remove all the dead tissue - more like a carefully managed reciprocating saw with a fine metal-blade on it... and I can't do any of that until the ants are gone. I suspect, to some extent, your reply is confirming what I am coming to grips with - that, sadly, the palm probably has to come down: the risk management and liability issues are manifest. Your spotlight helped bring that into focus: thank you.