Keep soil consistently moist but not waterlogged, especially during flowering. Water deeply at the base, allowing the topsoil to dry slightly between waterings. Reduce frequency in cooler weather.

Regular deadheading is crucial for Matthiola incana to encourage continuous flowering and prevent premature seed set, which can shorten its lifespan. Snip off spent flower stalks at the base. For bushier plants and more prolific blooms, pinch back young seedlings when they are about 6 inches tall, promoting lateral branching and a fuller display.

Matthiola incana is primarily propagated from seed. Sow seeds indoors 6-8 weeks before the last expected frost, or directly outdoors once the danger of frost has passed. Seeds require darkness for optimal germination, so cover them lightly with soil. While less common, cuttings can be taken from specific cultivars to maintain desired traits, though seed propagation is generally more reliable.

As an annual, Matthiola incana is not typically repotted multiple times. If started indoors, transplant seedlings carefully to their final outdoor location or larger containers once they have developed a few true leaves and all risk of frost has passed. Handle roots gently to minimize shock. Ensure the new pot or garden bed offers ample space for growth.