raft, boat
枋 centers on a simple wooden watercraft: a raft or small boat made of logs or planks.
枋 combines 木 (tree/wood) with 方, which likely contributes the sound. The character originally referred to a wooden raft or boat.
The left side 木 is wood, and the right side 方 looks like a square raft. Picture a wooden raft floating on the water.
For ホウ, imagine a wooden raft with a sail that catches the wind, making a 'hoe' sound as it moves: hoe -> ホウ.