Eiro was sitting on the ground looking at the flower that simply wouldn't grow all that much no matter how much of his magic he focused onto it directly. He would have to figure this out sometime later then. What was more important was that he had to get a little bit of practice in with the Nature Element so that he could possibly try and restrain the Collector, or even just trip him up somehow by creating an uneven ground.
Eiro managed to make other things grow pretty easily, like the weeds or the grass, luckily. He was able to control them somewhat, like making them flail around or grow into a spiral, and that seemed like he would be able to at least somehow use this magic already, even if it wasn't actually all that strong yet.