Paterson's curse (Echium plantagineum) — also known as Salvation Jane in South Australia, where it was once viewed with more ambivalence — is one of Australia's most familiar and most problematic pasture weeds. A native of the Mediterranean region, it was introduced to Australia in the nineteenth century and has since spread to cover an estimated 60,000 square kilometres of southeastern Australia, particularly in the cropping and pastoral zones of NSW, Victoria, South Australia, and to a lesser extent Western Australia and Queensland. For livestock producers, it presents a complex management challenge: in dry years it provides genuine grazing value as green biomass when little else is available, but chronic consumption causes pyrrolizidine alkaloid poisoning that can kill horses and damage the livers of cattle and sheep over time.

Identification

Paterson's curse is a biennial or annual herb — in most Australian environments it behaves as a winter annual, germinating in autumn with the first rains, growing through winter and spring, and dying after setting seed in late spring to early summer. The plant is highly recognisable in flower: dense spikes of purple-blue to violet flowers (occasionally pink or white) on branched stems that can reach 60 to 120 cm in height in good seasons. The flowering period — August to November in most of southeastern Australia — produces carpets of purple that can be visually striking across degraded pastures and roadsides.

In the rosette stage (autumn and winter, before stem elongation), the plant is a flat rosette of broadly elliptical leaves with a rough, bristly texture caused by dense stiff hairs on the leaf surface. The leaves are dull green to grey-green, 5 to 20 cm long, with prominent veins and a wavy or irregular margin. The bristly texture is distinctive — running your hand over a rosette leaf leaves a characteristic prickling sensation that distinguishes it from most similar-looking broadleaf weeds. Roots are a thick, fleshy taproot that can penetrate 1 to 2 metres into dry Australian soils, giving the plant remarkable drought resistance.

Seeds are persistent in the soil seed bank — Paterson's curse seeds can remain viable for 5 to 10 years in the soil, meaning that a property that appears to have controlled the weed can experience significant germination from the seed bank in subsequent wet seasons. This persistence makes strategic, long-term management essential; spot control of current plants without addressing the seed bank produces only short-term results.

Toxicity: which livestock species are affected?

The toxicity of Paterson's curse is caused by pyrrolizidine alkaloids (PAs) — a class of plant toxins present throughout the plant in all growth stages, with highest concentrations in young plants, seeds, and roots. PAs are hepatotoxic — they cause cumulative liver damage with repeated or prolonged consumption. The critical word is cumulative: a single exposure to Paterson's curse rarely causes acute disease in cattle and sheep; it is repeated grazing over weeks to months that builds to a threshold of liver damage causing clinical disease.

Horses and donkeys: by far the most sensitive livestock species to Paterson's curse alkaloids. Horses can develop fatal pyrrolizidine alkaloid poisoning from consumption over several weeks on pastures with heavy Paterson's curse growth. The liver damage — initially subclinical — progresses to hepatic insufficiency with signs including weight loss, jaundice (yellow colouration of the mucous membranes), photosensitisation (skin swelling and peeling in areas exposed to sunlight), neurological signs (walking in circles, head pressing, apparent blindness), and eventually death. The damage is cumulative and irreversible — there is no treatment for established PA liver damage. Keep horses off any pasture with significant Paterson's curse content.

Cattle: considerably more tolerant of PAs than horses, but not immune. Cattle grazing Paterson's curse as a significant proportion of their diet over several months can develop subclinical liver damage that reduces production (poor growth, reduced reproductive performance, reduced immunity) without obvious clinical signs. In drought years when Paterson's curse is one of the few green plants available and cattle are consuming it at high levels because alternatives are scarce, clinical disease can occur — weight loss, diarrhoea, photosensitisation, and jaundice in severe cases. Calves and young cattle appear more sensitive than adults. As a general management principle: if Paterson's curse makes up more than 20 to 30% of the diet over an extended period, liver function is being compromised even if clinical signs are not obvious.

Sheep: more tolerant than cattle, and considerably more tolerant than horses. Sheep appear to metabolise PA alkaloids somewhat differently, and clinical disease in sheep grazing Paterson's curse is much less commonly reported than in cattle or horses. However, chronic, high-level consumption does cause measurable liver damage in sheep, and wool producers should be aware that heavy Paterson's curse grazing in sheep can cause reduced wool production and weight loss — not through acute toxicity but through the metabolic consequences of compromised liver function.

Pigs and poultry: both species are more resistant to PA toxicity than ruminants and horses, and neither is typically at risk from incidental exposure to Paterson's curse in a mixed grazing system. This differential sensitivity is part of why some producers have historically used the weed as an emergency fodder source for sheep and cattle in drought — the risk is real but lower than its reputation sometimes suggests in the short term.

Grazing management during Paterson's curse seasons

The practical question for livestock producers in Paterson's curse country is not whether to control it (control is always preferable) but how to manage livestock on pastures where it is present in the current season. The key principles:

  • Never allow horses on pasture with visible Paterson's curse. The horse's sensitivity is sufficient that even moderate exposure over a few weeks can cause irreversible liver damage.
  • Monitor the proportion of Paterson's curse in your cattle and sheep diet. If the pasture is predominantly Paterson's curse (particularly in drought conditions when other species are brown and unpalatable), consider spelling the paddock or supplementary feeding with hay to reduce reliance on the weed.
  • Do not graze Paterson's curse seeds — seed heads contain the highest alkaloid concentrations in the plant. Graze pastures before seed set in September to October, or after seed shed if the rosette plants for the next year have not yet emerged.
  • Young cattle and sheep (weaners and lambs) should not graze high Paterson's curse pastures intensively — their smaller body weight means a higher dose per kilogram of bodyweight for a given consumption level.

Control options

Effective Paterson's curse control in Australian pastures requires an integrated approach — herbicide alone rarely provides lasting control because of the persistent soil seed bank. The most effective programs combine:

Herbicide application: selective broadleaf herbicides applied to the rosette stage (autumn to winter) provide effective kill of current-season plants before they set seed. Registered products in Australia include various metsulfuron-methyl formulations, and hormone-type herbicides (MCPA, 2,4-D, dicamba mixtures). Check current APVMA registrations and state label requirements before applying. Autumn application to the rosette stage is consistently more effective than spring treatment of bolting plants. A single year of herbicide without follow-up allows seed bank replenishment from any plants that set seed before or after the treatment window.

Competitive pasture establishment: Paterson's curse is most prevalent and most difficult to control in degraded pastures with low competition from desirable perennial species. Establishing competitive perennial grasses and clovers through renovation, over-sowing, or pasture establishment after herbicide control significantly reduces Paterson's curse regeneration from the seed bank over successive seasons. Maintaining ground cover above 70% prevents the bare soil that Paterson's curse requires for seedling establishment.

Biological control agents: CSIRO and state agriculture departments have released several biological control agents for Paterson's curse in Australia, including the flea beetle (Longitarsus echii), the crown moth (Eteobalea intermediella), and others. Biological control agents do not eradicate the weed but can reduce plant density and seed production significantly over time when populations establish successfully. Contact your state agriculture department or local Landcare group for information on biological control agent availability and establishment in your region.

Reporting and biosecurity obligations

Paterson's curse is a declared weed in several Australian states, meaning landowners have a legal obligation to control it. The specific obligations — declared weed status, control requirements, and notification obligations — vary by state and local government area. In some regions, failure to control a declared weed can result in the council entering the property and charging the cost of control to the landowner. Check the declared weed status and control requirements for your specific local government area before deciding on your management approach.

For more on pasture management for Australian livestock properties, see our Pasture Management Guide.

For more, see our Johne's Disease in Australian Livestock: Symptoms, Testing & Control and Bloat in Cattle: Causes, Prevention and Emergency Treatment for Australian Producers.