Willow trees are a larger species of tree that are fairly uncommon and are often spotted naturally growing near sources of water. Willow wood is useful as it provides a significant bonus to bows made from it, decreasing the difficulty of succesfully shooting the target. Willow fishing rods break less.
Like Oaks, willows kill all other trees and bushes within two tile of it while growing, due to their massive foliage blocking the sun underneath the tree. Crops and flowers are all that can be grown within this radius.
Willows appear to kill all trees and bushes within one tile (including diagonal tiles) after they reach the mature stage and all those within two tiles after they reach the old stage. It it also likely that willows start to cause invisible damage to all trees and bushes within the noted radius once they reach the noted age so the trees and bushes dont die right away, just once enough invisible damage is done.
NOTE: The other tree will only be killed when the willow moves to the next age level. Until then it will continue to grow and age as normal.
X=Kill zone from mature onwards
X=Kill zone from old onwards