I feel like I should warn the other participants of Masaru's training thread that I plan to have Masaru down there for the entire length (minus maybe a couple of days) of the 3-month timeskip (which is slated to happen after the end of the signing of the Accords, the Prison investigation, and a couple of those other shenanigans happening in a short time, though of course people can be posting things happening in that skip time). I did the calculations, and averaging 30 days in a month for 3 months is 90 days, or 90 months down there. Which comes out to about 7.2 years. I intend to have him stay down that entire time if possible.

I want him to work for this Bankai.

However, Frozen, I would appreciate knowing if that forest is just going to sit there forever, if it's going to attack him, or what. I want him to have a lot of open space for what is to come.

As for
I gave you a fairly precise lenght for it when I kicked the thread up on PM. If you've been counting, you'll know we're about half-way done. Three posts from the plant-creature, and my part in the thread is done. Then it's just Masaru and whatever you plan to do with him.
You never mentioned plant monsters. Maybe I was wrong, but I'd read that statement as being how long you'd spend having someone explain the nature of the training area to Masaru, not "THE TREES ARE ATTACKING!".

Anyways, if Li's Bankai can stay released for an entire year without interruption, feel free to have it do so.