How to grow/expand curves (polygons) until touch each other

I uploaded the Grasshopper file which I have to far, but I think I have to define each forest (hope you can see them on the map) block on a different curve component…

Basically I would like to let the different forest “island” grow as far as they create some woodland structure. A possible parameter might be, that for the first, they geow double their size or at least until the touch other woodland sections…ForSeriti-satellite