The Worst Herb Pairings: 7 Herbs You Should Never Grow Side By Side

Oregano and marjoram can unfortunately cross-pollinate and alter each other’s flavor profile. It doesn’t necessarily mean the herbs will taste bad or anything; they just won’t have the same flavor you would expect them to have, which definitely isn’t ideal.
If you have a large enough garden, you can plant oregano and marjoram in separate areas away from each other. If you’re planting in pots, plant them in separate containers, or else you’ll be faced with unnecessary trouble you don’t want to deal with.