I got 2 mini rose bushes on Valentines Day from Walgreens. About a week later one died completely, but the other seemed to be holding on. I read on here that I need to transplant and separate the plants that were in the pot(which turned out to be 5 of them, 4 living and 1 dead). By the time I did that, each plant had a dark line going all the way up the stem. They are all getting new leaves and all their roots seemed healthy. Can anyone tell me what this dark line is, if its something I should worry about, and any other care tips as these are my first mini roses ever. I'll try to post some pictures of them on here to hopefully show what I'm talking about. I only know how to post one at a time though. Thanks in advance!