Musky Storksbill (Erodium moschatum)
Musky storksbill is a broadleaf weed that often invades lawns, golf courses, and pastures, forming large flat rosettes that spoil the look and surface of turf. It’s particularly common in areas where grass cover has thinned from drought, compaction, or insect damage, and it thrives in bare or open soil.
In lawns, it’s mainly a visual nuisance, but in pastures it can also cause problems for livestock. The sharp, pointed seed heads can pierce the skin of animals and embed in wool or fur, though this happens far less often than with barley grass. Despite reports of mild toxicity causing photosensitivity in grazing animals, such cases appear to be rare.
Musky storksbill can behave as either an annual or biennial, depending on climate and growing conditions, and it’s most active through autumn and spring.
Identification
The plant starts life as a rosette, with leaves made up of oval leaflets arranged along a central stalk. The leaves radiate outward from a central growing point at ground level, often reaching 10–20 cm long, giving the plant a low, spreading form.
As it matures, musky storksbill produces slender prostrate stems that bear small pink to purple flowers (1–1.5 cm wide). Once pollinated, these turn into distinctive stork’s-beak-shaped seed pods, which twist into a spiral as they dry. The spiral awns respond to humidity by coiling and uncoiling, helping the seed drill itself into the soil — one reason this weed spreads easily in disturbed turf.
It can be confused with the closely related storksbill (Erodium cicutarium), which has more finely divided leaflets and prefers drier, poorer soils.
Why It’s a Problem
In lawns, musky storksbill disrupts turf uniformity and leaves unsightly rosette patches that are difficult to mow evenly. It also signals poor lawn health or compaction, as it usually establishes where turf has thinned.
In pastures, the stiff, barbed seed heads can be unpleasant for stock and reduce feed quality. Because it can establish quickly on bare ground, it often follows soil disturbance, overgrazing, or drought stress.
Management and Prevention
Cultural control methods:
- Maintain dense turf: Regular fertilising, overseeding, and irrigation reduce bare soil and prevent germination.
- Relieve compaction: Aerate compacted lawns to promote grass recovery and discourage weed seedlings.
- Mow regularly: Prevents flower and seed development, limiting spread.
- Improve drainage: Musky storksbill thrives where surface water or poor airflow encourages thin turf cover.
Chemical Control:
Musky storksbill is not easily controlled by standard broadleaf herbicides, so selective treatment and timing are crucial.
Effective options include:
- Picloram/triclopyr mixtures (NZLA Gold) – reliable control in turf and pastures when applied to young plants.
Avoid relying on clopyralid (NZLA BWC), as it has little to no effect on this species. Mixtures such as mecoprop/ioxynil/bromoxynil (Image) may suppress growth but rarely provide complete kill.
For the best results, spray while the plant is actively growing in the rosette stage, before it sends up flowering stems or sets seed.