I have had a Texas Hibiscus for a couple months now and it has done fine. It has continuously bloomed, and suddenly it started getting these black specks on its lower stalk. Also, half of the leaves started to go limp and turn yellow. There are even some fresh buds that have died. The places that already had blooms turned hard and brown. All the grass around the base is also dying or dead. I did use the Miracle Grow that hooks to the hose a couple days before, but all my other plants next to it are fine. Does anybody have any ideas about why this has happened? Maybe it's just the time of the season for this?