ShadyStump
Imperial Masterpiece
This seems too restrictive. I don't see why it couldn't be "Anytime between Jan 1 and Dec 31 2021..." If I want to pick a tree *later* than everyone else who started right away, that's not an advantage to me... and more importantly, this gives everyone a *full year* to collect native material and pick a submission.
In the northern hemisphere, I'm not going out to collect something from around my home between now and January 1, 2021 (absolute wrong time of year), which would limit me to nursery stock (really not many natives there, sadly, especially almost none in fall/winter) or seeds (giant disadvantage in a 5-year contest).
Otherwise, I like the idea of requiring a pot to be made by the submitter, from native materials. No purchased pots. Use a hollow log, or sticks, or gather clay and make a more traditional pot, or find a slate slab, or....... etc. This would add a real challenge and allow for a ton of creativity without extra rules.
I took this to mean, "announce your intent to participate," by January 1st. Your first few posts in your thread would be your thoughts on where to start, then select the trees you intend to direct toward the challenge, eventually over the course of the 5 years selecting just one for judging.