DaisyI said:Hmmm.... Good question.
Eric, you're up.
I'm posting from my small tablet, so multiple quotes and cut and paste aren't an option.
My test bag is taped to a wall, so the seeds are at various angles from horizontal or vertical.
Rick, the opening question was, "which end down
when planting?" So answers like "doesn't matter" are valid. You're the one who made it about radicles and roots.
Cgrooms, the only way I've
never planted a marigold seed is to stick it in the ground like a dart. I just lay them on the sides, the way they land when you drop them on a table or shelf. They grow fine for me that way, even in starter tray cells.