Foxtail Palm Trunk Bark Falling Off
G'Day! I have 2 foxtail palms in my front yard in Brisbane, Australia. I watered the smaller one hoping it would grow faster. Instead, the outer bark has fallen off in places revealing fibers underneath. 1 cm below these fibers is an inner trunk which is solid. The crown is healthy and sprouting new growth. I have 25 cm of topsoil with clay underneath. When I planted I dug out 1 cubic meter and filled with compost and black loam. Trees are 8 years old and over 2 meters tall. Should I worry about these patches of bark falling off? Also, I have lichen growing on the trunks of both trees. Should I use a pressure washer to remove this lichen? Thank you, Arnie.
Certified GKH Gardening Expert
Please do not pressure wash your palm! That lichen is not doing a bit of harm to your tree, but pressure washing sure will!
What it does signal, though, is that the tree is suffering from an infection, or stress. Probably fungal infection, though.
If I had to guess, it is an Armillaria fungus. Although without seeing any fruiting bodies near the roots, it will be hard to say.
It sounds like the palm is on its way out, as once the mycelium (White stringy fibers) has colonized the tree enough to see... It is too late for treatment.
You can attempt treatment with fungicides. This article will help: https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
DOLOMITIC LIME and WETTABLE SULFUR are also some of the best treatments for infections. Treat according to all packaging instructions.
This article will offer information on Armillaria rot: https://www.gardeningknowhow.com/plant-problems/disease/armillaria-root-rot-control.htm