Tagetes tenuifolia is the most refined member of the marigold clan, with finely cut, thread-like foliage that gives it an airy, almost ferny appearance quite unlike the bolder texture of its relatives. The flowers are small and single, typically golden yellow, carried in loose sprays across a rounded, two-foot mound of growth. When the foliage is crushed, a distinctly lemon-like fragrance is released that can persist for an hour or more, making it a natural candidate for planting along pathways and patio edges where passing contact activates the scent.

Start seeds indoors six to eight weeks before the last frost date and set out only once the soil has warmed. Signet marigolds prefer full sun and do not tolerate shade, but they thrive in a wide range of well-drained soils. Remove spent flowers before seeds set to extend the flowering season well into fall. They are reliable bee magnets and useful companions to tomatoes in the kitchen garden, where the foliage fragrance may discourage certain pests. Slugs and snails are the main hazard for young plants, particularly in damp conditions at the start of the season.