Newly planted pin oak: canker?

[Meulendijk]

A few months ago I planted two 3 (?) year old pin oaks, both of which are now showing strange black marks on the stem - more on one than on the other. It looks as though the bark turns black in a shorter or longer narrow stripe running up the stem, and then deepens, and seems to be lost, leaving a black indented patch. I have no experience of pin oaks other than what I read on them before deciding they would make a good addition to this bit of our grounds. We have quite a few mature and less mature other kinds of oak on the premises (robur, rubra, turner's, coccinea, petrae), none of which show this symptom. That's obviously how I'd like to keep things. So what could this be, and what do I do, if not simply get rid of them? See the added pictures for details.

 

[SDB777]

Looks as though bugs have eaten the outer bark.... Seen anything crawling on 'em?




Scott B

 

[Meulendijk]

Thanks Scott.

No, nothing crawling on them. I didn't attach other pictures earlier, that show that the black starts as a sort of wavy path up the stem, without indenting anything. Only later - I guess - does it turn like the first two photographs. A picture of what I think is an early sign is attached. This bit of black is still smooth with the surrounding unaffected green bark.

Jan Meulendijk

 

[Ed Roland]

Have pathology define the causal. Phytophthora spp can cause this type stem canker.

 

[treeseer]

how are the roots?