Abnormal yellowing of leaves, followed by abnormal amounts of leaf drop might be an indication of root die-off. How loose is your soil, and does it have any humus in it? Leaf mold and finished compost are really good at relieving stress in Salvias.

Where in SE Texas are you?
What is soil like Clay,Sand Etc..? FYI- my established
S.greggii will start yellowing & dropping leaves
when it gets dry.Here in Central Texas things are drying
out already.So some have began to drop the larger "Rain induced foliage" and started replacing them w/ smaller leaves for better drought tolerance.
The Plant you are describing sounds like S. microphylla
"Hot Lips".Ours is planted in some shade and a well drained mix.We will look forward to hearing back from you.
Art

watering every day sounds like too much! Especially if you have clay soil/poor drainage...

It seems to me that yellow leaves in many instances can mean over-watering. (sometimes it's iron deficiency, as in citrus)