Matthiola incana

Stock is a low-maintenance, cool-season, flowering, herbaceous perennial often grown as a biennial or annual, in the Mustard family. It grows easily from seed and can be sow directly outdoors, or started indoors 6-8 weeks before the last frost date.  Sow seeds in several two-week intervals to prolong bloom time. Stock is an upright, small shrub, reaching a mature height of 3 feet with oblong hairy grey-green leaves. The flowers have a clove-like fragrance so plant in areas where the scent can be enjoyed. The common name for this species comes from the woody base it develops. The genus name honors Pierandrea Mattioli, a sixteenth century Italian physician and botanist. The species name means hairy or gray-white in reference to plant leaves.

Stock does best in average to humusy, consistently moist, well-drained soils in full sun, but it does tolerate some light shade. It will not do well in acidic soil. Because plants begin to decline in the summer when temperatures are above 80 F., it is considered a tender perennial and is best used as an annual in the south.  These plants also suffer from hot night-time conditions.

A number of Stock varieties have been developed, mostly hybrids involving M. incana, M. sinuata and M. odorata, to the point where strict species plants are no longer available. The hybrids are available in a large variety of colors including pink, lavender, purple, white, yellow and red and bloom from late spring into fall under cool summer conditions. Bloom time is shorter in hot summer climates.

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common pests and diseases.

Diseases, Insect Pests, and Other Plant Problems:

There are no serious insect or disease problems. White mold can be an issue in mild, rainy winters.