White mustard prefers consistently moist soil. Water deeply when the top 2-3 cm of soil feels dry. Avoid waterlogging, as this can lead to root rot.

In hot, dry weather, you may need to water more frequently to maintain optimal soil moisture levels for healthy growth.

Pruning is typically not necessary for white mustard, as it is often grown as an annual crop for its seeds or as a cover crop. If plants become leggy or overgrown, you can lightly trim them to encourage bushier growth, but this is usually done for aesthetic or specific cultivation purposes.

White mustard is easily propagated by seed. Sow seeds directly into the garden bed in spring or fall after the last frost. Seeds germinate quickly in well-drained soil with adequate moisture.

Spacing depends on the intended use; for cover cropping, sow densely; for seed production, allow more space.

Repotting is not applicable to Sinapis alba as it is typically grown as an annual from seed directly in the ground or in larger containers from which it is harvested. If grown in a small container for a short period, it may outgrow it, but transplanting is usually for final placement rather than a standard repotting process.