What does it look like?
This plant is a sprawling perennial daisy (<40 cm tall) with fibrous roots, and long thin stems (from 15-70 cm long) that are sparsely hairy to hairless, much-branching, and root at nodes. Small, narrow leaves (upper leaves usually 3-lobed) are fragrant when crushed. White, white-purplish or pink daisy-like flowers with a central yellow disc (Jan-Dec) are followed by masses of fluffy seeds.
It forms dense mats and produces huge amounts of seed that travel long distances. It has wide ecological versatility, tolerating conditions ranging from moderate shade to full sun, damp to drought, and substrates from sand to mud. It can grow on almost any surface—including tree trunks, fern trunks, and loose gravel—and withstands both high and low temperatures
Why is it a problem?
Mexican daisy forms dense mats in a huge range of habitats. While it isn't very long-lived itself, it opens habitats up to invasion by vines and other weeds. It displaces vulnerable herbs, shrubs, and other native vegetation, particularly in ecologically sensitive or isolated areas. Seeds are primarily dispersed by wind, and occasionally by water. Common seed sources include gardens, roadsides, contaminated topsoil, and potting mix. Plant fragments can also be spread through the dumping of green waste.
Control methods
Physical control
Dig out small spots: Avoid any unnecessary soil disturbance and leave on site to rot down. plant material carefully. If seed is present, dispose of all plant material at a refuse transfer centre or burn it.
Herbicide control
- Spray with clopyralid (1ml/L) selectively. Or,
- Spray with glyphosate (10ml/L + penetrant in winter) or metsulfuron-methyl 600g/kg (2g/10L + penetrant (knapsack) or 15g/100L + penetrant (spraygun)).
- The plant is easy to kill but difficult to keep out. It can be crowded out with low, dense plants.
- CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
More information
Mexican daisy is widespread regionwide, particularly in urban and coastal areas.
Mexican daisy is a National Pest Plant Accord species. It is illegal to sell, propagate or distribute Mexican daisy.
Related links
Management Programme
National Pest Plant Accord (NPPA)
The NPPA is designed to prevent the sale, distribution and propagation of a set list of pest plants (the Accord list) within New Zealand. If allowed to spread further, these pest plants could seriously damage the New Zealand economy and environment.
More informationUnwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
Taxonomies
FamilyAsteraceae
TypePlants
GroupPerennial
HabitatLand
Management ProgrammeNational Pest Plant Accord (NPPA)Unwanted Organism
