I need some advise please on my ginger lily rhizomes. They never seem to grow and just stop at having a green bump. I have just placed them barely into the soil this year as I've had some of them rot in previous years. I'm not sure which way up they're supposed to be or anything. Should I have some growth by now? I put them in a pot at the beginning of may. I started them indoors but its been so warm they've been outdoorsfor quite a few weeks now.