They are in pots and I live in Austin, Tx. What is the white residue and how can I get rid of it? Some of the plants have dead leaves near the bottom of the plant. I water daily as they wilt?
If the white residue you are seeing looks like cotton, it's most likely mealybugs. I know that the plants I've grown over the years have had them. Neem oil usually kills the pest. always follow package directions.
The article at this link has further information on the plant: https://www.gardeningknowhow.com/ornamental/shrubs/african-bush-daisy/growing-bush-daisies.htm