Prostrate knotweed prefers consistently moist soil but tolerates drought once established. Water deeply when the top 2-3 cm of soil feels dry. Avoid waterlogging, as it can lead to root rot.

Reduce watering in winter when the plant is dormant.

Pruning is typically not necessary for Polygonum aviculare, as it naturally forms a low, spreading mat.

If desired for aesthetic reasons or to control its spread in small areas, it can be trimmed back lightly after flowering. This helps maintain its compact form.

Propagation is easily achieved through seeds sown in spring or by division of established plants in early spring or autumn. Cuttings can also be taken in late spring or early summer and will root readily in moist soil or a propagation medium.

Repotting is rarely needed for Polygonum aviculare, as it is often grown as a groundcover or in containers where it can spread. If grown in a small pot and becomes root-bound, repot in spring to a slightly larger container with well-draining soil.