Help. Disease or deficiency im unaware of.

Ok so here in michigan we have had an ass load of rain the past 2 months. I have several outdoor plants that all have worrisome signs. Most have some black stuff towards the center of new leaves and growth which is probably a mold of sorts due to rain. Im not super worried about those. The one I really need help with is in the pic. Anyone know what this is?

Oh and this came on fast. It looked totally healthy aside from some bug damage 3 days ago.

did u feed it something ? K deficiency they go light colored,K toxicity goes darker or so ive read.