Water prickly sowthistle regularly, especially during dry periods, to maintain consistently moist soil. Allow the top few centimeters of soil to dry out slightly between waterings.

Overwatering can lead to root rot, so ensure good drainage. Reduce watering frequency in cooler months.

Pruning is generally not required for prickly sowthistle, as it is an annual or biennial weed. If you wish to prevent self-seeding, remove flower stalks before they develop seeds.

Deadheading spent flowers will also help manage its spread in cultivated areas.

Prickly sowthistle primarily self-seeds, dispersing its seeds via wind and animals.

For intentional propagation, collect seeds from mature plants in late summer or fall and sow them directly in the garden bed in autumn or early spring. Germination is usually rapid.

Repotting is not applicable to prickly sowthistle as it is typically grown as an annual or biennial weed and is not a common container plant. If attempting to cultivate it, sow seeds directly into the desired location or a temporary pot, allowing it to grow and potentially self-seed.