How to Stack Multiple Trees Together?

[redgetan]

Currently, I'm using tiled, and I have multiple layers (i.e land, ground, blocks, foreground, etc..). The woodbase of a tree collides with the player, so its placed on the blocks layer, while the tree leaves themselves are placed on the foreground layer so that it covers a player sprite. Now, what my problem is that when I stack multiple trees together close to each other, it looks like this http://i.imgur.com/dtzGZXR.png . How do I ensure that there are no gaps and the tiles transition smoothly (i.e cover each other). Currently, I'm thinking one approach would be to create multiple foreground layers, and have the tree leaves placed on corresponding ones so that they overlap one another, but I feel like its a very manual process, and thought there might be a better approach.