Stock flowers were popular during the Victorian era and were commonly known as gilly flowers in England. They are considered signs of deep affection when given to others. Although often purchased as an annual, stock can easily be grown in home gardens. It makes a colorful addition to fresh bouquets, has long-lasting blooms, and also makes an excellent dried flower. The flowers are edible, with a delicate floral taste, and can be added to salads or as a garnish to desserts. Stock’s botanical name is Matthiola incana, and it is a member of the brassica family. The blue-green leaves do somewhat resemble tiny cabbage leaves, and when the flowers drop off the remaining foliage looks somewhat like brassicas gone to seed. There are at least fifty different Mathiola species; Mathiola bicornis, or evening scented stock, is a species with somewhat larger flowers. The original native species has been widely cultivated and hybridized, such that it now comes in a wide array of colors, from pleasing pastel pink and apricot to vibrant shades of crimson and purple. Some varieties grow up to 3 feet tall, though most are between 12 and 24 inches. The flowers may be tightly clustered or spaced somewhat loosely on the spiky stems, sometimes appearing as double blooms, and the leaves are narrow and oval.
Light
Stock flowers enjoy full sun but will bloom just fine in partial shade conditions, as long as they get at least 2-3 hours of sun per day; indirect sunlight will also keep them blooming. Too much hot bright sunlight will overwhelm them, so morning sun is better than afternoon sun.
Soil
These flowers like a rich, well-drained soil that has a pH close to neutral. If your soil tends to be acidic, you can add a bit of lime or wood ash to sweeten it, or use a commercial potting soil if growing in containers.
Water
Water regularly in the heat of summer, but be careful not to overwater, as this can yellow the leaves.
Temperature and Humidity
Matthiola incana is somewhat sensitive to temperature, which is what makes it a “half-hardy annual” in some locations, meaning it will keep blooming through one or two frost events. It likes cool weather, but cold winters may prevent it from returning as a perennial. It doesn’t like extreme humidity and so consistently moist, tropical conditions are bit ideal.
Fertilizer
Stock doesn’t tend to need fertilizer, but it’s somewhat particular about soil. A layer of natural mulch will help keep weed growth down and keep the soil evenly moist and cool for optimal growing conditions.
Pruning
Deadheading stock flowers after the petals wilt keeps the plants looking neat and may help generate new growth and possibly more blooms (this varies from one variety to another).
Varieties
There are many different varieties of stock available, owing to many years of hybridizing efforts to develop a wide range of colors.
‘Cinderella’ is a compact variety that grows no more than 12 in. tall, and has full double flowers in many beautiful pastel shades and some brights.‘Legacy’ stock grow up to 2 ft. tall and bear large double flowers in a variety of bright vivid shades including crimson and purple.‘Starlight Scentsation’ grows to 18 in. in height and bears dramatic clusters of single flowers in a range of colors.‘Iron’ is a series of large double flowered stock on sturdy stems in a range of colors, and the variety used by many florists for arrangements.‘Antique Pink’ features a two-tone pink flower that’s usually double; the colorful petals surround pale green centers, a very romantic look.
Growing Stock Flowers from Seed
Stock can be grown easily from seed, but should be sown early as it tends to wilt a bit in late summer heat. Sow them in rich neutral soil, barely covering with 1/8 of soil. Maintain good moisture by spraying but don’t oversaturate soil. Seedlings should appear within 10-14 days. As seedlings mature, you may pinch back budding growing tips for more dense clusters of blooms.
Common Pests and Diseases
Stock may be bothered by aphids, flea beetles, and cabbage white caterpillars. If you see pests on the leaves, gently remove them and cut off any damaged plant parts. They may also be vulnerable to the following diseases: fusarium wilt, gray mold, leaf spot, root rot, and verticillium wilt. Avoiding overwatering will help prevent most of these.