Stock (Matthioloa spp) perfumes the spring or winter garden, where winter is mild, with the fragrance of cloves. Native to coastal Mediterranean regions, this mustard-family plant grows commercially as an annual. Stock cultivars produce dense spikes of single or double blooms. The plants fade with the onset of hot weather.
Modern garden stock originated in the 18th century at London's Brompton Park Nursery, according to the Missouri Botanical Garden. This exceptionally fragrant variety of wild stock became the ancestor of the many stock varieties planted today.
The most familiar garden stock, Matthiola incana, often called Brompton stock, is available in a wide range of cultivars. Hardy to U.S.Department of Agriculuture Zone 7 and winter temperatures above zero degrees F, these plants stand from 12 to 30 inches high and up to 18 inches wide. Their columnar forms have downy, gray-green leaves and blooms in white and shades of pink, lavender, yellow, purple and red.
Opening to release its heavy scent late in the afternoon, night-scented stock (Matthiola bicornis) brings moths flocking to the evening garden. Spires of single, four-petaled pink or mauve blooms nearly conceal its silver-green foliage.
Where winters are harsh, nursery stock plants should go into the ground as soon as it's workable in early spring. They handle light frost. Stock will also grow from seed planted after the final spring frost date, advises the Missouri Botanical Garden. Where summers are hot, several plantings spaced two weeks apart produce continuing sets of vigorous plants that may last longer in the heat. Plants from fall-planted seeds will bloom in winter where the climate is mild.
Moderately drought-resistant, stock tolerates shade but performs best in full sun. It liked humus-rich, consistently moist, well-drained soil but isn't fussy about soil type. It grows in acidic to slightly alkaline sand, loam or clay, according University of Florida professor Edward F. Gilman and Teresa Howe, research coordinator of the University's IFAS Cooperative Extension.
An erect, uniform appearance makes stock plants natural choices for formal flowerbeds, planted in groups of like colored and similarly sized plants. Appealing in containers, they're a striking contrast to trailing or otherwise more loosely structured flowers. Their fragrance enhances any freshly cut flower bouquet. Older cut stock flowers, however, develop an overpowering scent of cabbage.