What does it look like?
Ragwort (also known as Senecio jacobaea) is a member of the daisy family. It’s an erect, annual to perennial herb and usually grows to 45-70cm tall but can reach 1.6m high. It has reddish-purple stems and wrinkled, divided leaves, which are dark green on top with a downy lining. Leaves appear in a rosette that grows into a dense cluster. Its flowers are bright yellow and appear in clusters. Downy (fluffy), parachute-like seeds are present.
Ragwort prefers areas of open space with some area of bare ground for seeds to germinate in, particularly in high rainfall areas. It will invade open forests, riverbeds, swamps, pastures and coastal areas. It also tolerates a wide range of environmental conditions, except for shade. It’s especially abundant in areas of higher rainfall.
Why is it a problem?
Ragwort is an aggressive, prolific flowering plant that colonises exposed areas, i.e. paddocks. It matures quickly and may reduce the productivity of the land, along with out-competing native plant seedlings.
The plant is toxic to grazing animals, directly affecting the liver by increasing its ability to accumulate copper. However, animal deaths from ragwort poisoning are not common, as cattle, deer and horses selectively avoid grazing it. Sheep will eat ragwort without any apparent adverse effects, unless they are continuously exposed to it in large quantities, or if they are not used to feeding on it.
Control methods
Herbicide control
Spray rosette plants (winter to spring only, before stem formed) using 2,4-D (50ml/10 litres (knapsack) or 1-3 litres/ha in 300 litres water (boom spraying)). O
Spray: Cut any seedheads and dispose of by burning or deep burial then apply glyphosate (100ml/10L knapsack) or metsulfuron-methyl 600 g/kg (5g/10L knapsack) ensuring entire plant is covered.
Plants damaged by cutting, digging, pugging, mowing, or poor spraying often regrow, developing multiple root crowns (multicrown) and becoming perennial, meaning they flower each year without dying. These plants do not respond to 2,4-D herbicide, requiring tougher, more residual herbicides.
Ragwort can be left in regenerating bush and shrubland as it will disappear as light levels decrease.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
Biological control
The ragwort flea beetle and cinnabar moth are widespread in the region and are well established where they occur.
More information
Ragwort is listed as a Sustained Control pest in the Hawkes Bay Regional Council Regional Pest Management Plan 2018-2038 and is subject to Plan Rule 18 relating to Boundary Control.
Related links
https://www.nzpcn.org.nz/flora/species/jacobaea-vulgaris/
https://www.nzflora.info/factsheet/Taxon/Jacobaea-vulgaris.html
https://www.weedbusters.org.nz/what-are-weeds/weed-list/ragwort/
Management Programme
Sustained Control Programme
Sustained Control exists to hold well-established pests at an acceptable maximum. However, the costs of management and control grow in-step with the size of the invasive population. Because cost:benefit returns can fall to 1:5 or less, most of this work is focused on specific sites of high ecological value. While the spread of these pests between neighbouring properties remains the predominant risk, in some cases control within properties is still sought and warranted. A sustained control programme will hold populations to maximum acceptable limits over the period of the RPMP.
More informationRules
Plan Rule 18
All occupiers shall, on receipt of a written direction from an Authorised Person, destroy all;
a) Bathurst bur and variegated thistle plants within 5 metres of the property boundary
b) Blackberry and gorse plants within 10 meters of the property boundary
c) Nodding thistle and ragwort plants within 20 meters of the property boundary
on land that they occupy where an adjoining occupier is also destroying or the land is clear of:
a) Bathurst bur and variegated thistle plants within 5 metres of the property boundary
b) Blackberry and gorse plants within 10 meters of the property boundary
c) Nodding thistle and ragwort plants within 20 meters of the property boundary
Council will administer the rule upon receiving a written complaint from the adjacent land occupier and/or at the discretion of the Authorised Person.
Taxonomies
FamilyAsteraceae
TypePlants
GroupGroundcover
HabitatLand
Management ProgrammeSustained Control Programme
RulesPlan Rule 18
