If you don't get a good answer here, please send this pic to the Harris County Agricultural Extension Agent, or go to their office, it's in Bear Creek, on Hwy 6. Don't think anyone would be there today, though. This is pretty serious, whatever it is!

Hard to diagnose with just that picture but first suspicion based on info provided is oak wilt. Def contact the Extension Office and hopefully they have someone who knows or a referral.

I think a picture of the black part of the trunk you were talking about might help. Sometimes mechanical injury and kill the bark and when it starts to rot and it gets wet it turns black

Almost looks like green algae from excessive moisture. Is there a sprinkler system that sprays on the tree?

Eahamel and WxDano, I have followed your advise and sent the inquiry with pictures to the Ag Extension Agency.

Alabamatreehugger, there is a sprinkler system in the yard that turns on for 1 hr twice a week during the year and I have had turned off since late November.

hey

on what basis .... is the title based??

who defined such as a FUNGUS????

second.. as bark is basically dead EXTERIOR material.. i dont understand.. how something on the surface.. of an INTACT bark.. can kill a tree ...

all we have to go on.. is your words.. and you are throwing around some very precise terms.. and i wonder if you are doing that intentionally .. to inform us .. or unintentionally confusing us ...

e.g you could paint the hole tree for 8 feet from the ground.. like they used to.. with thick white lead based paint ... and have no impact on the interior of the tree ...

now.. new house??.. any excavation on the landscape?? .. how did you decide that one hour once a week is 'good' for you plants in houston.. what is the native soil type.. how long have they been planted onsite?/ ... etc .. other than death.. and green stuff.. and some slight indication of watering.. you really havent given us much to go on

the purp plum.. has a life expectancy of 10 to 15 years.. period.. if it was that old.. its probably a life span issue ...

more facts please ....

ken

I hope you sent more than one pic because no diagnosis is possible with that one.

I see nothing abnormal in the photo. More than likely the purple plum and oaks died of different causes. More photos are needed and even then, diagnosis can require lab testing to be sure.

Since these were planted so recently, my first thought that this is a planting problem.

The green stuff is probably just moss or lichen. Most trees in my area have a patina of lichens on them, especially in sheltered areas like creek valleys.

As to the powder at the base of the tree, that's what you need a picture of. The blackish color at the base of the trunk is probably a rot or mold of some sort, and that could be what did those trees in. Did you over-water? 1 hour 2 times a week doesn't really seem excessive. When it's dry, I usually water tree & shrub plantings with overhead sprinklers for 2 hours every 10 days, and that seems to work, even in drought.

chiming in with rhiz.. that looks like one heck of a big transplant ... we need more history on how they were 'well planted' .. by whom.. soil amendments.. warranty??? .. etc ...

ken

WxDano,
I believe it was Dan's Default Rule #1: Improper Planting.

FYI: Dan was a former poster here that was a professional in the business. Having seen so many issues with planting, he basically assumed it was improper planting until/unless evidence of something else was presented.

Arktrees

I've never seen a green fungus.
Algae yes, but not fungus.
Mike

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.

LOL.........wanted to add that just because the green on this tree is dry and powdery, it doesn't preclude that it isn't algae. I spent every spring for the last quarter century cleaning algal growth from greenhouse walls before starting a spring crop. It was caused from dampness on the skin from intermittant watering, especially with nutrient enriched watering and during the cropping season was soft and velvety, but after a fallow rotation when it wasn't exposed to water, dried hard and then flakes off like powder. I suspect that in Texas right now, one isn't running their sprinkler systems?