I'm looking to plant mint in a drainage ditch that's about 80 feet across and 20 feet deep. I love mint tea, but I can't seem to keep it alive in pots. I don't think planting it in the ditch would be a problem for the next decade or so. I'm in zone 8b, and the area is mostly shady with plenty of moisture in the lower parts. I can't water it regularly, but I'm willing to do some light fertilization. What's the best way to ensure the mint takes root? I'm concerned that throwing seeds might be obstructed by leaf litter, and planting plugs seems like a lot of work. How do I choose the best spot? Could the slope wash away seeds or small plants? And will the higher areas still get enough water?
3 Answers
I recommend against planting mint directly in the ground without some sort of containment, like a barrier, because it can be really invasive. Once it's in, it can take over pretty quickly! It's great that your ditch will likely provide moisture, but just be cautious about how much you let it spread.
Honestly, I’ve thrown mint into dry areas without watering and it just thrived! I say just toss a few plants into the ditch and see what happens. Chances are, they'll spread like crazy before you even notice it!
I wouldn’t suggest letting mint go completely wild in that ditch. Instead, plant some mint and keep it pruned regularly. As long as it gets some sunlight, nitrogen (like from fish fertilizer), and enough moisture, it will spread quickly through its underground runners. Just a few square feet should be enough for your mint tea cravings!

Thanks for the advice! I guess I just need to be ready for a mint explosion!