General
Annual flowers that are sometimes listed as Gillyflowers.
Latin
Matthiola longipetala (syn. M. bicornis, also Cheiranthus longipetalus)
Family: Brassicaceae
Difficulty
Challenging
Season & Zone
Exposure: Full sun to partial shade
Zone: 2-10
Timing
Sow indoors 6-8 weeks before last frost, or direct sow outdoors after last frost. Seeds take 3-20 days to germinate at an ideal soil temperature of 12-18°C (55-65°F).
Starting
Stocks are very susceptible to damping off. Sow on the surface of vermiculite under bright light, with some ventilation nearby. Water only from below. Pot on into sterilized potting soil once plants are large enough to handle, and space them in the garden at 15-23cm (6-9") apart.
Growing
Moist, well-drained, fertile soil is best, with a neutral to slightly alkaline pH. Pinch out side shoots for taller plants. Crowding plants encourages earlier blooming. Water regularly and feed lightly every month.