I've noticed that after a month or so since buying, leaves of my Hypoestes phyllostachya is becoming brown and then dry out and colors are somewhat fading. I keep it in front of a south side window, that is a little bit open and shady. The weather is cold here.I water it whenever the soil gets dried, every week or 10 day. What do you recommend?
According to this page, you should keep the soil moist during the growing season. Perhaps you're letting it dry out a bit too much.