Grove of the First Tree

Grove of the First Tree enters the battlefield tapped.
{2}, {t}: Add {w}{b}{g} to your mana pool.
{w}{b}{g}, {t}: Gain 1 life for each card in your graveyard. Then, if you have 30 or more life, put
a +1/+1 counter on each creature you control.
Rest for the living, vengeance for the dead.