Stock Flower Seeds - Matthiola incana Flower Seeds

In most temperate climates, the sweet spot for sowing Matthiola incana seeds is four to six weeks before your last expected frost in spring, or in late summer to early fall in regions with mild winters. Cool season flowers like stock need soil that has not yet warmed to summer temperatures, so timing is more important here than with many other annuals. In climates with hot summers, fall sowing generally produces stronger plants and more abundant blooms than spring sowing.

Stock flower seeds germinate most reliably with some exposure to light, so avoid burying them deeply. A very light dusting of soil, just enough to maintain contact and moisture, is all that is needed. Keeping the surface moist and the seedbed in a bright but not hot location gives the seeds the conditions they need to sprout.

Choose a pot at least ten inches deep to accommodate the root system, and use a well-draining potting mix rather than dense garden soil. Position the container where it will receive full sun in the morning and some protection from intense afternoon heat, since containers warm up faster than the ground. Water consistently, as pots dry out more quickly, and feed every two to three weeks with a diluted balanced fertilizer once the plants are actively growing.

The most common reason stock plants fail to bloom is heat. If temperatures rise above about 75 degrees Fahrenheit before the plants have set their flower spikes, they often stall or bolt without flowering properly. Another frequent cause is sowing too late in the season, giving the plants insufficient cool growing time. Check also that your plants are receiving at least six hours of direct sun, as shade significantly reduces flowering.

The petals of Matthiola incana are edible and carry a mild, slightly spicy flavor that matches their clove-like scent. They are used occasionally as a garnish on salads or desserts, and their fragrance makes them appealing in drinks and floral syrups. That said, only the petals should be consumed, and as with any edible flower, you should be certain no pesticides or other chemicals have been applied to the plants.

Ten weeks stock strains carry a useful trait where seedlings destined to produce double flowers tend to be slightly paler or more yellow-green than their single-flowered siblings at the cotyledon stage. When the first true seedling leaves appear, move your trays to a cool location around 50 degrees Fahrenheit for a night or two and observe which seedlings show a lighter color in their seed leaves. Removing the darker-leaved seedlings and keeping the lighter ones shifts the planting toward doubles, though the method is not perfectly precise and results vary with conditions.

Cut stock flowers typically last five to seven days in a vase when handled well, though this varies with room temperature and how freshly they were cut. Recut the stems at an angle before placing them in clean, cool water, and change the water every other day to slow bacterial buildup. Keeping the arrangement away from heat sources and direct sunlight extends the display noticeably.