The Flipped Normals team posted a look at creating foliage from particles in Blender.
There are likely a ton of ways along with custom tools to make plants and other foliage in 3D. With Blender, you can also use some of the built-in tools to create stunning foliage.
“In this free tutorial, we’ll be going through how to make stunning foliage using only the built-in tools in Blender. No tricks, no paid addons, just good ol’ Blender!”