Bulleen Art And Garden
? 2021

Land Cress (Barbarea vulgaris and Barbarea verna) releases chemicals which attract the Diamondback Moth (right) and the Large Cabbage Moth (left) – both small brown moths which are common pests in the vegie garden. These moths lay their eggs in the Land Cress, subsequently the emerging caterpillars feed on the Land Cress, are poisoned by the saponins in the leaves and die. So if you hear Land Cress referred to as a ‘Dead End Trap Crop’ – that is why.
Also worth noting is Land Cress – Barbera verna – is a nice spicy addition to salads.

Do NOT confuse Diamond Moth and Large Cabbage Moth with the Cabbage White Butterfly. Confusion of these names has led to an unsubstantiated belief that Land Cress is a Dead End Trap Crop for the Cabbage White Butterfly (Pieris rapae). Landcress attracts the butterfly, but does not kill its caterpillars. You can use it to trap the caterpillars, then pull the plant out and bin plant and pests. Alternatively, once you have a nice infestation building up on your land cress you can give it a spray with Dipel, hopefully breaking the pest infestation cycle without having to spray the vegies.

Read more: https://www.baag.com.au/land-cress-a...-pest-control/