How to do tree of flower blowing in the wind?

I guess one way is to rig a model of a tree and animate it manually.
How would one do this procedurally?
Basically to give each bone in model a bit of give or springiness?

Is there a way to procedurally do this in Blender or Unity3D so the trees/flowers could respond to a wind force?

 

Providing the mesh on the flower model is fine, you could use the cloth component which response to the windzone.
as for procedurally generating them the flowers. If your terrains max height is 10 and lowest is -10 then you'd call your vertices and instantiate it on vertices[v].y then you could do

Code (CSharp):

1. if (vertices[v].y >= 6) {
2. // instantiate your model here but remember to grab the vertices position using flowerPos
3. }