I have wild P. caerulea plants living in my area and I tried to grow the plant from cuttings. I put them in water (changed the water daily) and they started to root! However, when they started rooting the top half of the leaves (I cut the bottom half because I heard it helps with the rooting) started to turn yellow and wilt. So, I planted the cutting in a pot. Unfortunately, the plant continued to die. I would I prevent the cuttings from dying?