I'm probably having to relearn alot about Texas gardening since I spent 13 glorious years on sandy soil in Colleyville. Now I'm in Fort Worth on black gumbo. Lots of lava sand, green sand, mulch (mostly cedar), organic fertilizers both general and specific to species have been added to the soil in the 8 years we've been here. Most everything is doing well considering the heat. My water bill is running over $100 a month keeping things moist. However, the garden phlox in one bed - plenty of air, east sun - comes up fine, sets buds, blooms and begins dying from the bottom up. I can't find any white spots which would indicate powdery mildew. Everything else in the bed is doing okay which belies nematode damage. Now the forsythia in the other bed is dying off branch by branch. It has done this before and come back. It sits under a pansy forest redbud in a bed with perennials. I am totally stumped. Any ideas?