Tropicals & Tender Perennials: EE leaves brown on edges, 1 by 2pugdogs

2pugdogs wrote:
I have a xanthosoma sagittifolium that I got off ebay. It has two new leaves. On the edges of the new leaves there are some brown marks. I have it in a 13 by 13 in. pot sitting in front of a south window, my house temperature is around 63 at night and 69 durning the day. I am keeping the soil moist. I planted it in Miracle-Gro Moisture Control Potting mix enriched with miracle-gro plant food. Can someone help me out by telling me what I am doing wrong, or not doing.