Weedbusters isn’t about the everyday garden weeds that sprout in your vege patch or flower beds.

Weedbusters focuses on invasive plants—the kind that spread aggressively and threaten ecosystems, damage the economy, and risk the health of people and animals. These weeds don’t just annoy gardeners – they smother native plants; disrupt landscapes, making it harder for wildlife to thrive and communities to manage.

What do we mean by ‘weeds’?

There are a lot of different weedy words used to describe weeds by different organisations for different reasons:

For example:

• Environmental weeds: listed by the Department of Conservation (DOC) as threats to conservation land.
• Pest plants: Declared by regional councils and unitary authorities under their regional pest management plans.
• National Pest Plant Accord (NPPA) species: Banned from sale/propagation nationwide.

For simplicity, Weedbusters, calls them all ‘weeds’.

Why worry about weeds?

Weeds are reshaping New Zealand’s landscapes at an alarming rate.

New Zealand currently has 386 plant species classified as environmental weeds, with another 1,800 species beginning to naturalise—spreading independently without human assistance. In addition, around 25,000 exotic plant species are present across the country, most still confined to gardens. This is more than ten times the number of native plant species, highlighting the scale of potential future weed threats. Only a handful of invasive weeds have ever been fully eradicated.

They threaten our unique biodiversity:

• Choke forests, wetlands and waterways
• Displace native plants and destroy wildlife habitat
• Block breeding sites and reduce food for birds, fish, and insects.

They hurt our economy too:

• Farmers and foresters lose tens of millions of dollars yearly in control costs and lost production
• Hydro lakes struggle with weed blockages that hinder electricity generation
• Councils and DOC pour millions annually into weed control in natural areas.

How did these weeds get here?

People brought them. Over 75% of New Zealand’s worst weeds started as garden plants—chosen for their beauty but escaping into the wild.

New Zealand is home to over 25,000 introduced plants in gardens and nurseries. A rough rule of thumb:

• 10% will establish in the wild (naturalise)
• 10% of those will become serious pests, outcompeting native species and disrupting ecosystems

How it happens:

• Imported garden plants ’jump the fence’ and spread
• Garden waste is dumped in reserves or roadsides, where weeds take root and invade
• People sell weedy plants at weekend markets and online (like Facebook Marketplace)

Spreading weeds is a people problem, but it’s also a people solution. What we plant, how we dispose of garden waste, and how we manage our land all shape the future of New Zealand’s biodiversity.

The soaring cost of weeds

Weeds are a growing cost burden on:

• Councils and DOC managing parks, reserves and public land
• Farmers and growers protecting productivity
• Volunteers and communities working to restore nature.

The longer we wait, the harder and more expensive it gets.

Every dollar spent on early intervention saves thousands on future removal and restoration.