Does Hilchos Kilayim (mixed plants) for Zeraim (not trees or grapes) apply outside of Eretz Yisrael? If there is some application outside of EY, to what extent is it Assur? Specifically I’d like to know if I can plant several herbs and vegetables next to each other in the same large pot.

It is a generally accepted Halacha and tradition that Kilayim Zeraim does not generally apply outside of Eretz Yisrael, and one is allowed to plant several herbs and vegetables next to each other in the same pot.