Grove of the Guardian — ruling 1

To activate Grove of the Guardian’s second ability you can tap any two untapped creatures you control, including ones you haven’t controlled continuously since the beginning of your most recent turn.

Grove of the Guardian — ruling 2

You can’t tap Grove of the Guardian to activate both abilities at the same time.

Grove of the Guardian : règles, fonctionnement et interactions (MTG)

Grove of the Guardian is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

: Add . , , Tap two untapped creatures you control, Sacrifice this land: Create an 8/8 green and white Elemental creature token with vigilance.

How it works : Grove of the Guardian

Original English text — Wizards of the Coast / Scryfall

#1October 1, 2012· Wizards of the Coast
To activate Grove of the Guardian’s second ability you can tap any two untapped creatures you control, including ones you haven’t controlled continuously since the beginning of your most recent turn.
No other card is named in this ruling.
#2October 1, 2012· Wizards of the Coast
You can’t tap Grove of the Guardian to activate both abilities at the same time.
No other card is named in this ruling.