I want to try using rupturewort to edge my lawn so I don't have to use an electric edger. I bought seeds; the instructions said it was hard to germinate, but just a few days after I sowed it into coco plugs the seeds germinated. That was about two weeks ago. They still look like little threads. I'm keeping them moist and yesterday gave them a little fertilizer. They get part sun in a window. How do I get them to grow large enough to transplant?