They smell like carrots when you break the fading blooms off, they tolerate high heat and full sun, and they are pretty. Flowers for gardens, not arrangements.
Geraniums do well controlling invasive beetles, and local humming birds also seem pleased. Some of the smaller flower variety are pleasantly scented, and easy to clone. However, it is not a good plant choice for people with pets.
Mustard (Sinapis alba) is nice if you like pleasant smelling little yellow flowers, low-effort resilient plants, and spicy food. =3