An annual or occasional biennial when late germinated seedlings carry through to the following year. It is an ephemeral plant as it can mature and produce seed quickly in a few weeks, giving rise to several generations in a year. As it is a member of the Cruciferae Family and related to the mustards, the leaves are milder in flavour to Rocket, but make a tangy addition to a salad - they are best picked when the plant is young before the flowers appear.
The seed capsules explode at the slightest touch when they are mature, dispersing their contents widely. They are also edible having a more intense peppery taste than the leaves.
The small, white flowers have four petals and can be found for much of the year.
The height is up to 15cm, but can vary depending on the soil conditions.

Hoe or hand pull before flowering, remove uprooted plants if flowers or seed capsules are present as they can mature and disperse the seed if left lying on the ground. Tackle in early spring as removing the first plants of the season should reduce the numbers later. Also when planting remove the top 3 or 4 centimetres of the compost as many bought in plants have a ready supply of seed, if not the weeds themselves, dwelling on the surface.
Weedkillers to use:-
A residual herbicide should prevent germination on paths.
Paraquat, Diquat contact action gives an immediate knock-down, so it should not have time to set seed, if caught in time.
Using a flame gun weed burner on the soil or paths will destroy the plants and any seed on the surface.

Very similar is Wavy Bittercress (C. flexuosa) which grows slightly larger - up to 23 cm. The stalks on the leaves do not have hairs and the flowers have six stamens whereas Hairy Bittercress flowers have four, but growth is similar.
The flower stalks and long seed pods are similar to Thale Cress, but the pods on the latter protrude sideways whereas on Bittercress they are more vertical. See also New zealand Bittercress.

Follow these links for further details on Weeds, Weed Removal and Weed Prevention.