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WEED GUIDE

How to identify and control bittercress

Tiny plants colonise damp greenhouse surfaces, pots and paths rapidly. Learn how to identify it, choose the right control method and prevent it returning.

13 sections
Bittercress identification photograph
Bittercress: identification photograph

Identification

Bittercress is a low rosette weed that thrives on damp greenhouse benches, pots and paths. Its slender seed pods stand above small white flowers and burst readily when mature, making pot hygiene especially useful.

Tiny plants colonise damp greenhouse surfaces, pots and paths rapidly. Its main route of spread is exploding seed pods. Check the crown and roots as well as the leaves: those features help distinguish a seedling that can be hoed from a plant that will need follow-up.

UK seasonality and timing

Inspect regularly in spring and autumn.

Bittercress is chiefly a seed-bank problem: remove young plants before seed matures, then revisit ground where its exploding seed pods may leave another flush.

Crops and plants affected

Bittercress is not a crop parasite. It affects vegetables and flowers where it competes for space, light and water or obstructs access to beds. Tiny plants colonise damp greenhouse surfaces, pots and paths rapidly. Give priority to seedlings, newly transplanted crops and plants sharing the same small bed; a separated patch is less urgent if it cannot spread into cultivated ground.

What damage does it cause?

Tiny plants colonise damp greenhouse surfaces, pots and paths rapidly. The impact depends on how densely it grows and how close it is to a crop. A few plants outside the bed rarely justify disturbing a whole plot; growth among seedlings or over crop foliage is more likely to reduce establishment and make harvesting difficult.

For bittercress, persistence comes from exploding seed pods. Removing leaves without addressing that route clears the surface briefly but leaves the source of another flush in place.

Prevention

Pull before pods mature and keep surfaces weed-free. Do this before the plant spreads further, and clean soil from tools before moving to an uninfested bed. Keep bed edges visible so new shoots or seedlings are spotted early.

For bittercress, mulch or close-spaced crops reduce bare ground but do not stop established plants. Hoe seedlings before they flower and replenish the exploding seed pods.

Control and management

  • Pull before pods mature and keep surfaces weed-free.
  • Improve drainage and avoid leaving damp bare compost.
  • Inspect regularly in spring and autumn.

Wildlife-friendly and soil-conscious control

For bittercress, use a low-disturbance method suited to its growth: Pull before pods mature and keep surfaces weed-free. Work only the affected patch, check before disturbing wildlife shelter and avoid salt, household vinegar or washing-up liquid, which can damage soil and nearby plants.

Improve drainage and avoid leaving damp bare compost.

Long-term management

Inspect regularly in spring and autumn. Recheck after cultivation and rain for seedlings, and keep cleared beds cropped or mulched so bare soil is not left open for another generation.

Common mistakes

Do not brush ripe pods across nearby pots.

Compost before seed pods develop.

If it keeps returning

If the same patch reappears, check below the point where the leaves emerge. For a seed-spreading weed, the next useful step is improve drainage and avoid leaving damp bare compost. Repeat at the timing described above rather than repeatedly cutting the visible leaves alone.

If bittercress appears in a neighbouring bed, trace whether the route is exploding seed pods and contain that edge first. Avoid carrying contaminated roots or seed heads across the plot.

Frequently asked questions

How do I keep bittercress out of greenhouse pots?

Bittercress is a low rosette weed that thrives on damp greenhouse benches, pots and paths. Its slender seed pods stand above small white flowers and burst readily when mature, making pot hygiene especially useful. Pull before pods mature and keep surfaces weed-free. Remove flowering plants before seed is ripe.

When should I tackle bittercress?

Inspect regularly in spring and autumn.

Can I compost bittercress?

Compost before seed pods develop.

Why can bittercress keep coming back?

It spreads by exploding seed pods. New seedlings may emerge from seed already in the soil; remove them before they flower.