Black grass

Black grass grows annually to a height of 1m and has hairless green or purple leaves. It is a serious issue for winter crops as contaminates seed lines and has become resistant to some herbicides.

Description

• Leaf sheaths are open.
• Seedheads are initially green but mature to red-purple, appearing black from a distance.
• Sets seed in autumn and germinates in spring.
• Dispersed by contaminated seed, hay, machinery, vehicles, gravity and seed can survive animal digestive systems, particularly cattle.
• Habitats include crops, pastures, grasslands, roadsides, and wastelands.

What you need to know

A serious issue for winter crops, reduces yields, increases cultivation costs and contaminates seed lines, impacting exports. It has become resistant to several herbicides in Europe making it difficult to control.

Management approach

Black grass is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.

Control

Do not attempt to undertake control of black grass yourself. Report sightings to the MPI on Exotic Pest Hotline at 0800 80 99 66 or the online reporting form.