Rigging this tree

Hi all,
I’m a pure novice in rigging so I need some help.
I want to move/stretch the blue tree when the top pink plane is moving. Si I need some unique bone controlling the others (?)
I suppose I must add an armature with some bendy (?) bones to the tree but I failed so I removed them.
The tree branches must be stretch when the plane is moved as well.

Thanks

DNM_04.blend (685.4 KB)

Solved the problem with a lattice modifier.