In BfM you will discover Mulch Bags in your Old Shack > Other Stuff tab.
Tree Mulch can be placed in any of the two Orchards in Bellflower Meadow as a Mulch Tree Ring to help the Tree retain ground moisture, reducing the time fruits ripen by 15%!
How does it work?
1. Place the Mulch on an Orchard.

2. Add Tree Beds over the Mulch Tree Rings
Trees will still require Tree Beds before you can plant them. So, add Tree Beds over the Mulch Tree Rings.

3. Add Trees from the Shop
The Orchards in BfM accept only regular Trees from the Shop > Trees menu.

