Is this Gloomy Scale?

[adamrabung]

Hi,

My 15 year old Red Maple has developed a black coating on about 4 feet of its trunk, around where the first branches branch off. There are very small orange dots on the black part. I can scratch the black stuff off with my fingernail. Is this Gloomy Scale? Is there anything I can do? Thank you in advance!

Thanks,
Adam

 

[ATH]

Looks like it.

Scrub it off with a scotch pad.

Make sure the tree is in a good growing condition. Pull a little of that mulch off of the trunk. Does it have a good root flare, or is that buried (unfortunately, many trees are planted too deep)? If it is buried, excavate a little around there. Widen the mulch ring - but make it no more than 2-3" deep and NOT against the trunk. Don't use landscape fabric under it. Give the tree some extra water if it is a dry spring or summer.

Spray with horticultural oil...now would be good before they hatch then again at egg hatch (should be +/- late-May for you in VA).

You could also do a dinotefuran treatment (bark spray or soil drench - it is a systemic).

Don't use a nitrogen fertilizer...that will feed the scale more than the tree. One benefit of widening the mulch ring is the tree will get less of the N from the yard fertilization.

 

[adamrabung]

Really helpful, I appreciate the detailed response.