Answer: I'd check the amount of water your hibiscus is receiving. If it's on a drip system, the emitter may be clogged. If you're watering by hand, a deep soaking twice a week should help it perk up. Tropical hibiscus remain evergreen in Arizona and flower most profusely during the summer months. Sudden wilting is nearly always a water issue - or a root rot problem from poorly draining soils. Hibiscus can take any amount of pruning. Because flowers are produced on new growth, I regularly prune mine back by 6=12" several times during the growing season.
Best wishes with your hibiscus!
Q&A Library Searching Tips