Here’s a sampler.
Wallflower (Erysimum) is not commonly grown here in the Midwest, but it does well here if you can find it. Some are rated as winter hardy in Indiana, but they are not reliable.
I grew ‘Jenny Brook’ wallflower, a Blooms of Bressingham introduction, for three years, where it wintered over in a window box left outdoors with no protection.
You’ll find wallflowers in mixed spring containers or possibly as premium size bedding plants. Grow fragrant wallflowers in full sun to part shade in average soil. It gets about 15 inches tall and works well in rock gardens or mixed with perennials. Wallflowers are yellow, orange
Stock (Matthiola) is an extremely fragrant flower, especially at night. The fragrance is a common ingredient for perfumes.
Stocks do best in full sun and average soil. They rarely get taller than 12 inches. The colors are shade pink, rose, white and mauve.
Stock also can be found in combo pots for spring and occasionally as premium size annuals. They also are easy to grow from seed.
Snapdragon (Antirrhinum majus) comes in all heights and colors. They do best in full sun and average, but tolerate part shade. Snaps can be cut for indoor arrangements. Look for them in individual premium annuals sizes or bedding plant trays in garden centers.
Although they thrive in cool temperatures, they have staying power in the summer garden, too. About half way through summer, cut back snaps by about half and they will get a second wind that carries them well into fall. I’ve had snaps bloom in December before.
At garden centers now, you’ll find pansies (Viola wittrockiana), and their smaller cousins, Johnny jump-ups (V. cornuta or V. tricolor). Johnny jump-ups may go dormant in summer, but pop right up in fall and again the following spring. Plant in sun or part shade.