Most plant leaves are scentless, however, there are herbs and herb like plants that produce wonderful aromas when brushed against. Fragrant foliage plants intermingled with perennials in the garden can result in long lasting aromas throughout the growing season unlike a sweet flower that lasts a few weeks or days. Fragrant leaves dry very well and retain most of their aroma. Dry and mix leaves with dried flower material for a delightful potpourri.
Listed below are a few plants that grow well in this area and can be incorporated in the flower garden with ease. Try to plant next to paths, where the leaves would be brushed against gently as one passed by.
Thyme (many varities to choose from).
Mint (can be very invasive, plant in container).
Scented Geraniums(grown as an annual in Zone 5. Plant in container or dig up in late Fall and store in house). Rose Geranium has a powerful aroma).
Wintergreen-creeping perennial ground cover that grows a few inches tall. White flowers in Spring and red berries in Fall.
Plants that emit a citrus aroma would be lemon thyme, lemon verbena, orange, lemon and grapefruit scented geraniums and lemon grass. All of the above with the exception of lemon thyme are tender and must be housed indoors prior to the first frost. You can take cuttings and propagate new plants that are easier to house during the winter.
Exceptionally fragrant perennial, biennial, and annual flowers can be added to enhance the fragrance.
Planting a fragrance garden can be fun and very enjoyable to the senses, especially when a summer breeze circulates the aroma through open windows in the house. There are many more plants to numerous to mention but if you're interested, I'm sure you can get further information from your local nursery.