Matthiola (Matthiola incana) is more commonly known as Stock. It is a flowering annual that is native to Europe. Matthiola is hardy in all zones, but regarded as a tender annual because heavy frost kills it. Matthiola can grow between 12 and 30 inches tall and comes in a wide assortment of colors. Including pink, blue, yellow, magenta, purple, and white. When in bloom, matthiola are a flower garden highlight and they are prized for their lovely, spicy-scented fragrance. Plant matthiola in full sun, or very light shade, and make sure it receives humus-rich, loamy soil.
Fill up planting cells with good quality seed starting compost until it's about 1/2 inch from the top of the rim in each cell. Pack down the seed starting compost using a small block of wood, the back of a spoon, your fingers or any object which will compress the soil. Make sure the soil has been well firmed down.
Place the planting cells into an irrigation tray that has 1 to 2 inches of water in it. Allow the soil in the planting cells to soak up the water until you can see the soil has been visibly moistened. If there is any water left standing in the irrigation tray, drain it out.
Sprinkle 3 to 4 of the matthiola seeds over the surface of the seed starting compost in each of the cells. Push all the seeds firmly into the soil using a block of wood, or the back of a spoon. Sprinkle no more than 1/4 inch of the seed-starting compost over the matthiola seeds.
Set the tray in a warm location. Try to keep the temperature between 60 and 65 degrees F. Germination of matthiola seeds typically begins between 7 and 14 days. Keep the soil in the planting cells moist, but never so it is soaking wet. Add water to the irrigation tray as needed.
Move the tray near a strong source of light as soon as the seeds start to emerge. Ideally, they should be provided between 8 and 10 hours of light daily. If you don't have a sunny window to place them in, you can place them 4 to 6 inches away from fluorescent light for 12 to 14 hours daily.
Plant the matthiola seedlings when they've grown to a manageable size, approximately 2 to 3 inches tall. You can pot them up into larger containers, or plant them directly in your flower garden.