Hiya, from Zone 9 across the gulf. Something to smell great, how about some dwarf citrus such as meyer lemon or blood orange. The spring blossoms are as good as it gets on fragrance. Those do well in our zone 9. Pentas may not be so fragrant but they thrive in the humid heat of summer, very attractive to the eye and hummingbirds. Rangoon Creeper is an excellent trellis worthy vining shrub that thrives in humid heat and produces intoxicatingly fragrant blooms. Star jasmine is another that can be ground cover or grown up trellises. Gardenias, those are beautiful shrubs that produce showy white flowers that perfume the air all around them. Coreopsis, Coneflower, Asters are other fragrant possibilities.
Veggies, herbs, now with May and summer it will be getting hot. I think okra is pretty and thrives in summer heat. There’s a ton of varieties, some grow red pods, others green. Blooms are like a hibiscus bloom. Basil smells wonderful and loves the heat. There’s dozens of types with a variety of colors. Some are purple leafed. Some are ruffled. Cardinal basil produces showy blooms. Pesto perpetuo is variegated. Vining squash and gourds produce showy large yellow or white blooms, some like moschata types do better In heat. Luffa goard can be eaten when young. Purple hull peas and red noodle asparagus bean look pretty with color you can eat and grow well in summer time in zone 9.