Here's a thread to post mistakes that we consciously made because hey, it seemed like a good idea at the time. Learn from us!
Here's mine for the day, and I apologize that it will be too specific to be useful for those here but maybe a lurker will find value in it: A few years ago I was testing orange iris. I wanted to identify the best oranges and to compare their color, viability, and bloom time. So I thought it would be a good idea to plant them all in a row, next to each other. I carefully labelled each one. Yeah, that lasted all of one garden season and the next year when the shitty children across the street devastated by marking system, all of the tags were pulled out of the ground and scattered everywhere. Now I don't know which orange is which. I may have been able to identify them it I had scattered the orange iris all around the yard because the tags would have been in the general vicinity.
your turn...