Vitex. why are the leaves turning black?

[Roddmol]

So I purchased a Vitex at the end of winter. Chopped it back and gave it some better soil. It spring to life and was growing really well. Then suddenly the leaves start to turn black. I found what looked like aphids on some of the leaves. I used dish soap and water and the aphids have been gone for a week now. The tree looks better than it did a week ago but I'm still worried. Any ideas on what is causing this?

 

[JoeH]

you repotted it? I know when I transplanted mine from the ground to pots they stressed and dropped leaves then rebudded right back out. Looked a lot like that. I'm sure the Aphids weren't helping either.

 

[Roddmol]

I scraped some of the old soil and roots from the sides and removed about 1/3 from the bottom. Then put it back into the same container. That was a couple of months ago though

 

[sorce]

1/3

Soil or roots?

What did the roots look like?
Amount?

Could be mites/pests still.

Or roots..
Sorce