If you are looking for a tough, self-sufficient plant that doesn't mind being ignored, Ladybird Sunglow (also called Texas Primrose) is the plant for you. These are heat tolerant plants with sunny yellow flowers, that love well drained soil.
Calylophus Ladybird Sunglow
Plant Habit: Mounding, trailing
Water: average, DO NOT overwater
Fertilize: Once a week
Spacing: 8 - 12"
Height: 4 - 8"
Width: 12 - 20"
Exposure: Full sun
Attracts bees, birds and butterflies
Very Heat and drought tolerant
Works great as a filler in hanging baskets