Careful Cultivation, Umbral Mantle, and Zirda, the Dawnwaker

Prerequisites

• Careful Cultivation on the battlefield
• Umbral Mantle on the battlefield
• Zirda, the Dawnwaker on the battlefield
• Umbral Mantle and Careful Cultivation attached to the same creature you control that does not have summoning sickness

Steps

1. Activate the creature with Careful Cultivation and Umbral Mantle attached by tapping it, adding
2. Activate the creature by paying and untapping it, causing it to get +2/+2 until end of turn
3. Repeat

Results

• Infinite green mana
• Infinitely large creature until end of turn