Fertilid
Amulet of Vigor
Felidar Retreat
Heartbeat of Spring

   Prerequisites

What do I need to start this combo?
All permanents on the battlefield.
Fertilid has at least two +1/+1 counters on it.
1 available

   Steps

How does this combo work?
1
Activate Fertilid, searching your library for a basic Forest card, putting it onto the battlefield tapped.
2
Amulet of Vigor triggers, untapping the land.
3
Felidar Retreat triggers.
4
Resolve the Felidar Retreat trigger putting a +1/+1 counter on each creature you control.
5
Tap the land for .
6
Repeat.

   Results

What do I get from this combo?
Near-infinite +1/+1 counters on creatures you control
Near-infinite landfall triggers
Put all basic Forests from your library onto the battlefield