AusBonsai

I’ve noticed peppermint trees used as hedges here in Perth and they always look really shabby.
What I mean by that is the foliage always looks sad flat and old. I went against my instincts and ended up buying one from a local nursery in the hope of proving myself wrong about the species.

Anyway I repotted this tree and pruned it 4 months ago. Today I was inspecting it again and Thinned it out. Half the tree has what looks like
variegated Foliage.
I’m not sure if it has a disease or is being attacked by an insect but the new grown is just really weird, weak and sad looking. Some of the leaves not many are deformed. A few have crispy burnt edges but again not many.

Is anyone able to explain what’s going on with this tree please?

Sent from my iPhone using Tapatalk

I assume you did not buy a variegated variety? Sometimes the variegations don't show up at certain times of the year.

Some variegations are the result of virus infection. Maybe that's what has happened here? Obviously not fatal or we would not have variegated varieties for very long so not as bad as it may sound.
I've never heard of variegation being from insect infestation except when they transfer the virus.

If this is a new variegation you could name it and start propagating. New variegated plants usually sell well as many gardeners like something a bit different. Try propagating some cuttings from the colored branches and see if it persists in new plants.