Horehound

Horehound is a perennial erect downy bushy herb around 50cm tall with small white flowers. It is unpalatable to stock and can contaminate meat and wool.

Description

Leaves are wrinkled, light green, densely covered in small hairs and are in opposite pairs.
Flowers are small and white in dense clusters along the stem.
Seeds are contained in the lower portion of the flower which has hooks and breaks off when brushed against something e.g., wool and fur.
Seed is dispersed by animals (stock and feral), clothing, equipment, and machinery.
Habitats include dryland pastures, grasslands, shrublands, and wastelands.

What you need to know

Reduces access to pasture and avoided by stock due to bitter taste and furry texture. Can contaminate meat and wool.

Management approach

Community Led

These organisms have not been legally declared as pests but may be of interest to the public as they occur regularly in the environment. They may be capable of causing adverse effects to the values of Waitaha/Canterbury.

Consider removing this invasive species from your property and consult your local council for appropriate disposal.

Control

Site management

Well-managed grazing and sowing improved pasture species and using appropriate fertilisers can prevent establishment.

In arable land, cultivation will destroy seedlings, but established plants may need blade ploughing of repeated efforts.

Topping horehound can remove flowers and improve stock access to pasture.

Physical control

Dig or pull out seedlings and small infestations.

Plant parts requiring disposal: all parts.

Contact your local council for appropriate disposal locations.

Chemical control

Several herbicide products can be used as foliar spray to control individual plants or small patches. These include products containing glyphosate, chlorsulfuron, hexazinone, metsulfuron-methyl, triclopyr and fluroxypyr. However, some of these can persist in the soil for months and impact desirable pastures, crops, and natives.

Sowing lucerne and then conducting a winter treatment of herbicide can provide effective control.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Biological control

Biological control agents currently available for this species: