When normal, scheduled, growth occurs two to three times per day trees that have been chopped but not removed should regenerate one or more chops. Currently this part of the game is not working.
The same is true for normal rocks in the mine: normal rocks include "Craggy Rock", "Ancient Rock", "Chunky Rock", "Rough-hewn Rock", "Dark Rock", etc.
Mushrooms (rocks), Flame Crystal rocks, and Crystal rocks do not regenerate.[1] (Note: Raven Woody says Flame Crystals do regenerate? In any case if they were last Mondayish they will again, if they weren't before they won't when this is fixed)
However once you have less than 25% of your rocks remaining in your mine new rocks, including these three special rocks will grow [2]
Vitalin Crystals are another special case. Vitalin Crystals no longer regenerate if partially chopped and they are no longer part of regular regrowth. If you have no vitalin crystals at all only one 4-chop one will grow as part of normal regrowth [3]
Regular new rock growth and new tree growth are not effected by this bug. If you have trees in less than 50% of the squares in your fair you should get new trees. If you have rocks covering less than 25% of the squares in your mine new rocks should grow.
LOLapps hopes to fix the regeneration issues very soon!
[1] *
May 17 Patch List
[1] *
[COMPLAINTS] Partially Chopped Mushroom Rocks in the Mine do not Regenerate
[2] *
[POTENTIAL BUG] No New Special Rocks - Mushroom/Fire Crystal/Reg Crystal
[3] *
[COMPLAINTS] Changes to Vitalin Crystals and Vitalin Gems