I'm trying to build a self-contained automated tree farm with redwood trees. The main problem I have is how to replant saplings. So I thought I would use a BuildCraft filler with height 1 to fill in the area with saplings. The problem is that in testing, a filler will only plant a single sapling and never move beyond that:
You can see the result in this image. The filler is programmed with nine bricks in fill mode, and powered by a full redstone energy cell. If I take the redwood saplings out of the resource area of the filler and use cobblestone for example, the area is instantly filled up as expected. But then if I use redwood saplings, it stops like the picture above with just a single sapling in the corner.
Is there a way to get this to work, or is there some limitation to a filler that prevents using saplings? Is there another method in Feed-the-Beast to replant saplings over a large area?