Although the medium in which you are reading this does not do justice to the subject, odor is such an important aspect of gardening that I can't just ignore it. The smells of blossoms are often extremely evident, but many types of foliage have even more overpowering scents. Some, like lantana, are repulsive to many people, while others, including many culinary herbs, can make a person's mouth water.
We grow several kinds of herbs that could be used in cooking, but rarely actually use them to that end. Rosemary (Rosmarinus officinalis) is very well adapted to our climate and is a satisfying plant to grow. There are at least a couple cultivars that assume different forms, including an upright type that can be pruned like a hedge. The plants we have tend to sprawl, never grow very high, and need to be pruned away from neighboring plants every so often. Rosemary is evergreen and weathers our winters quite well while also surviving the heat and drought of summer, although it seems to prefer shade to sunny locations. The leaves of the plant can be added to many types of food and I'm especially fond of rosemary in bread or dumplings. The smell of the plants is pleasant and not too overwhelming so pruning it is enjoyable. Besides the dark green needle-like leaves, another attraction of this perennial is its occasional light blue flowers.
My favorite smell of all comes from a plant that barely survives for us. Lemon verbena (Aloysia triphylla or Lippia citriodora) is supposed to be a tender shrub that grows to 10 feet, produces thick foliage and even flowers. For us, it is a one foot tall stick with a couple of small branches of leaves. That is it. It loses the leaves during the winter but comes back in the spring. It has never flowered and does not grow any bigger. We've had the single plant for at least 7 or 8 years now, and at first it was being crowded out by other plants. I moved it and it doubled its branches, from 2 to 4. The only reason I keep the little plant free of invading neighbors and give it extra water in the summer is because it has the most delightful, real lemon-like smell of any plant. Just touching the leaves gives off a scent like lemon candy. Anybody who is lucky enough to be able to grow this shrub successfully should take full advantage and have it near paths or walks so that people can touch and smell it whenever they walk by.
The last plant here is absolutely the strongest smelling one we have. My husband likes the smell but I find it a bit overpowering. Copper canyon daisy (Tagetes lemmonii) is an evergreen sub-shrub that grows a couple feet tall and spreads a lot. During the winter it can freeze back some, but often not completely to the ground and so does well if pruned back to encourage compact growth; it also does best in full sun. It is wonderfully drought resistant and tends to repel deer as well, so it makes a good landscape plant for people in the hill country west of Austin. Other names for this plant include lemon marigold, Mt. Lemmon marigold, and Mexican bush marigold. Copper canyon daisy spreads easily because the ends of branches that touch the soil will root. This plant is related not to daisies, but to the common garden marigold. A native of the Huachuca Mountains in Arizona, copper canyon daisy was discovered in the late 1800s by a husband and wife botanical collecting team whose last name was Lemmon, hence the Latin name. Although I've read descriptions of its smell as being "lemony," I suspect that is assumed from the name and not from the actual smell, which is more like an extremely strong mint or medicine odor. It takes only a touch to produce the aroma and pruning these plants can be quite an experience. Copper canyon daisy blooms in the late fall, producing bright yellow flowers in abundance if there is enough rain.