Magriculture

Aftershock {1}{b/g} (You may cast this spell for its aftershock cost with mana produced by lands. If you do, lands that produced that mana become Wastes.)
Until end of turn, Wastes you control gain
"{t}: Add three mana in any combination of black and green to your mana pool."
"The Eldrazi seek to destroy our home, and we must flee ahead of them. But we will leave nothing behind for them to destroy."