The Grove

If you're finding there simply aren't enough packages out there to learn, why not check out The Grove? I read about this plugin for Blender in 3D Artist. It's essentially (another) procedural vegetation generation tool, that enables a fair level of user control. It has native support for Cycles. It may not have all the power of SpeedTree but it's also a fraction of the price, and no doubt has a flatter learning curve.

Pretty cool!