Marsh Cudweed thrives in consistently moist soil. Water regularly to keep the soil damp, especially during dry spells. Avoid allowing the soil to completely dry out, as this can stress the plant.

In its natural boggy habitat, it receives ample moisture, so aim to replicate these conditions in cultivation.

Pruning is usually not necessary for Marsh Cudweed. If the plant becomes leggy or overgrown, you can lightly trim it back to maintain a more compact shape.

Deadheading spent flower stalks can prevent unwanted self-seeding if that is a concern, though it is often an annual.

Marsh Cudweed is easily propagated by seed. Sow seeds directly outdoors in spring as soon as the soil can be worked, or start them indoors a few weeks prior.

It readily self-seeds in suitable conditions, often behaving as an annual or biennial.

Repotting is rarely needed for Marsh Cudweed, as it is often grown as an annual or tends to self-seed. If grown in a container and it outgrows its pot, repot in spring into a slightly larger container with a well-draining, moist potting mix.