Click the flag to generate a new plant thingy. That's about it. If your plant starts drawing way off to the side, try generating a new one.
I've seen some cool curly plant-like drawings somewhere before, so I felt like recreating that. It's not perfect, but this is just a quick project and I just wanted to make a simple version. These last few weeks of school are busy for me, so I can't promise any bigger projects, tutorials, or codegolfs until next Saturday. This will have to suffice for now. ;)