Giant buttercup

(Ranunculus acris)

Boundary Control Pest

Giant Buttercup is a hairy perennial with basal leaves that are present all year round. It grows up to 150 centimetres tall and produces yellow flowers in October. The plant is freeseeding and these seeds may be spread by machinery, water and animals. Seed may be viable for at least 20 years. The plant’s preferred habitat is pastureland in high rainfall areas.

Reasons for the Strategy

Tall stalks with yellow flowers on top of broad green leaves.

Unpalatable to cattle, Giant Buttercup can quickly overwhelm pasture species in dairying areas, thereby reducing pasture and dairy production. Once established, the plant is costly to control. Being palatable to sheep, it is not generally a threat to sheep and beef farms.

Giant Buttercup is assessed at “6” on the infestation curve. It is widespread in the pastoral areas of the Tasman-Nelson region. Requiring boundary control of Giant Buttercup is the only practical option and the benefits it provides outweighs the minimal costs of enforcing this requirement. The Management Agency will continue to promote the development and distribution of biological control agents. Advice will also be provided to occupiers to assist in preventing the spread of Giant Buttercup in hay and equipment.

Objective

To control the spread of Giant Buttercup from adjacent properties to land clear of Giant Buttercup, or being cleared of Giant Buttercup.

Alternative Measures

The alternative option of “do nothing” or relying on voluntary control will not prevent the spread of Giant Buttercup to adjacent properties where it is being controlled. The Strategy rule for Giant Buttercup provides some protection for occupiers who are controlling Giant Buttercup. Requiring a greater level of control, instead of just boundary control, is not appropriate given the widespread distribution of Giant Buttercup, the high cost of control, and that the occupier is the main beneficiary.

Strategy Rule for Giant Buttercup

The occupier shall destroy all adult and juvenile forms of Giant Buttercup located up to 5 metres from the boundary of the land that he or she occupies when the adjacent property is clear or being cleared of Giant Buttercup. A breach of Strategy Rule 6.3.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Explanation of Strategy Rule

The Management Agency will limit its intervention to enforce compliance of the rule to occasions when a reasonable complaint is received from an adjoining land occupier. This would require the complainant’s land to be already clear, or being cleared of Giant Buttercup, and that
any invasion of the pest plant through the boundary has the potential to cause economic harm to the complainant’s land.

Biosecurity Act Requirement

No person shall knowingly sell, propagate, breed, release or display commercially, Giant Buttercup, under Sections 52 and 53 of the Act.