I'm not sure which Ruellia species you have as there are several with quite different growth. Deadheading is not usually needed but I have noticed the dwarf types like Katie do leave an unsightly dead bloom laying around on the plants. That said I have never known anyone to bother with trying to deadhead them. That would indeed be a daily chore!
The loss of foliage points to some type of stress such as drought, soggy (poorly drained) soil, or some other root related problem. I suggest watching the watering so as to keep the soil moist but not too wet.
Thanks for the question. Please stop in again soon!
Q&A Library Searching Tips