Tree trunk base

[Crlyn1234]

I have 3 Bottle trees , the oldest being 4 years old. From the ground up,
about a foot, the trunks are very dark brown, almost black. Otherwise, the
trees look healthy. The soil is very bad, full of caliche and rock. Do you
have any information on this problem? Thank you

 

[John Paul Sanborn]

I did a quick search http://search.dogpile.com/texis/search?q=Brachychiton+rupestris&geo=no&fs=web

Seems they like rocky soil and can tolerate a wide variety.

They seem to be an arid clim plant, do you water often? could be a problem.

Hire someone to look at them.