"Shake" effect for Speedtree Trees

I got a way
Im blending speedtree wind with impulses of simple grass wind, with lerped strenght.
Im still looking for a way to mask the tree, so the simple grass wind works correctly, now the trunk shakes as much as the tree tops
Inyone have an idea how to paint vertex color mask on speedtree asset?

Hi.

Im working with speedtree trees implemented with speedtree wind in UE4 and it works fine.
What i need to do is to make them shake by the hits of an axe, once the tree is being cutted down.
Any idea how to make this, having in mind that this should blend good with the wind animation? In the ideal case it should work with the speedtree weights, used for the wind.

Thanks in advance