Weeping Willow
You can play two additional cards on top of this. (This doesn't allow you to immediately play more cards.)
When scoring, this is worth 2 VP per Pile in your YARD that doesn't have any cards on top of it (GRASS and DIRT are Piles and are not "cards.")
Pests or any other cards on a Pile will disqualify that Pile from being counted. (The Pile that your WEEPING WILLOW is on is never counted because it has a card on it.)