Catnip is yellowing

[SunshineAndSoil]

So, my catnip plant that I started from seed earlier this year has been yellowing for some reason. It was over-flourishing, so I pruned it back a little, could that have anything to do with it?

 

[Tetters]

If you cut it all back right down to the soil, it will regrow again.

 

[SunshineAndSoil]

Yeah, I know. It's in the mint family, and we all know what that means.