When talking about logs forget that inch per year stuff, that's only a rule of thumb for planks that are stickered. Past 2" or 3" it doesn't apply.
I do two things when I cut trees down.
1. If I want the wood to spalt, I stand the log upright on dirt and seal the exposed end with tar. I cover with a trap and check often. Woods differ, birch will start spalting in a month during the summer and in three months its trash. Maple may take a year before it is starting to look nice.
2. I cut logs in half, seal the ends with anchorseal and store horizontal out of the elements.
But this is not an exact science, if you plan on using the whole tree for pens, it may take you years to use up the whole tree. In many cases the wood may no longer be useful. Find some turning friends around you and share the wealth. Maybe when they come into some wood they will return the favor.