Algae are often the precursor of fungii as seeb in lichen growth where they form a symbiotic relationship. The algae sets up the conditions the fungii needs to develop. I've had trees go greeen like that before eventual lichen formation. The first thing I'd suspect in the tree deaths is the black lesion near the ground. I found one last year in a twenty year white oak, oozing wetness. Just out of curiosity, I pulled out a knife and figured I'd see what was hidden by the bark and started cleaning the gunk out, figuring if it was some sort of cancre, I wouldn't do any more harm than what was already occuring. Found some sort of fat, white larva inside the lesion. Cleaned it and hollowed out the hole (size of a golf ball out) and told the tree it was on its own. The wound looked pretty clean and dry going into winter and I'll have a look at it come spring to see if it tries to form callus. I suspect any lesion at ground level. Lost a few tulip poplar from them after only a year or two of decline.

These plants thrive in a low Ph area-below 7.0. I would guess that the one chair which receives some overspray has moss growing on it as you may have low Ph water. If I recall Teak is a neutral to higher Ph wood so would not support the moss and lichens without the water. You can buy Ph paper it comes in rolls at most drug stores if your interested to see what your water's Ph is. Regardless a low Ph is a prerequisite for good moss and lichen growth along with moisture. Putting granular or powdered lime down a few times a year will usually take care of the problem. Scott

Great shot GreenLarry!

so it is very true then that if a tree is supposed to only live like 20 years and you've already squeezed that plus more years out of it, that if you do drastically chop/top it (like that english guy did to those apple trees) and then wait for new suckers to form into a tree, that it is true that those new suckers aren't as if you'll get another healthy 20 years out of the tree, because the older root system is still there, correct?