Making growable plants collidable?

Hey i made a new plant all is good i can grow it ect but i would like to make it collidable since its just a static mesh and not a BP how do i do this i tried making just a simple box component and set collision in there but it dosent change a thing?

you can add a collision mesh to the object through the static mesh viewer. From there you can set the features of collision that you want.