Why You Should Never Grow these Invasive Plants in New Zealand
Blog Overview:
New Zealand’s delicate native biodiversity is constantly threatened by invasive plant species, which are non-native organisms that grow aggressively and lack natural predators. While often introduced as attractive ornamentals, these plants can quickly choke out native flora, degrade ecosystems, and potentially make your garden non-compliant with local regulations.
In this blog you’ll learn:
- What Are Invasive Plants?
- Invasive Plants to Avoid in Your NZ Garden
- How Jim’s Mowing NZ Can Help You Garden Responsibly
Why You Should Never Grow these Invasive Plants in New Zealand
New Zealand is world-renowned for its unique biodiversity — from lush native bush to vibrant birdlife. But that delicate balance is easily disrupted by invasive plant species. While some of these plants might look attractive in the garden, they can choke out native flora, degrade ecosystems, and even become illegal to grow or distribute.
We’ll highlight some of the worst offenders — and explain how Jim’s Mowing NZ can help you avoid them and keep your garden healthy, legal, and low-maintenance.
What Are Invasive Plants?
Invasive plants are non-native species introduced—either accidentally or intentionally—into environments where they don’t naturally occur. While they may seem harmless or even decorative at first glance, these plants can wreak havoc on local ecosystems. Unlike native plants, invasive species often have no natural predators, pests, or diseases in their new environment, which allows them to grow unchecked.
They typically:
🌱 Grow Aggressively
Invasive species often grow faster and taller than native plants, quickly dominating the landscape. This aggressive growth allows them to monopolize light, water, and nutrients — leaving little or no room for native species to survive.
🐛 Lack Natural Predators
In their home environment, these plants might be kept in check by insects, animals, or diseases. In New Zealand, however, those natural controls are missing, allowing them to spread far beyond garden boundaries into native bush and reserves.
🏞️ Disrupt Native Habitats
By overtaking natural areas, invasive plants reduce the biodiversity that makes New Zealand’s ecosystem so special. Native birds, insects, and other wildlife that rely on indigenous plants for food and shelter can be pushed out of their habitats.
🔥 Create Fire Hazards and Erosion Risks
Some invasive plants, like gorse and pampas grass, are highly flammable and increase the risk of wildfires. Others replace deep-rooted native plants with shallow-rooted invaders, making soil more vulnerable to erosion and landslides — especially in hilly or coastal areas.
Invasive Plants to Avoid in Your NZ Garden
While many invasive plants were originally introduced as ornamental species, their ability to spread rapidly and dominate native ecosystems has made them a serious threat to New Zealand’s environment. Here are some of the most problematic species that should never be planted — no matter how attractive or easy to grow they seem.
1. Old Man’s Beard (Clematis vitalba)
Old Man’s Beard (Clematis vitalba) by Hectonichus, licensed under CC BY-SA 4.0.
This climbing vine may look like a lush, flowering plant, but it’s a nightmare in bush environments. Old Man’s Beard grows rapidly and climbs up trees and shrubs, blanketing them in dense foliage. This prevents light from reaching the plant below, effectively strangling and killing native species. Once established, it’s extremely difficult to remove and can alter the entire structure of a forest ecosystem.
2. Woolly Nightshade (Solanum mauritianum)
Woolly Nightshade (Solanum mauritianum) by Umberto Ferrando, licensed under Creative Commons Attribution 4.0.
This fast-growing shrub or small tree is toxic to humans, animals, and insects. Its leaves and berries contain solanine, a compound that can irritate the skin, eyes, and lungs. Woolly Nightshade competes aggressively with native plants by seeding prolifically and growing in disturbed areas. Birds spread its seeds far and wide, making it a long-term threat to natural and residential spaces alike.
3. Wandering Willie (Tradescantia fluminensis)
Wandering Willie (Tradescantia fluminensis) by Ixitixel, licensed under CC BY-SA 4.0.
This low-growing groundcover might seem like a handy way to cover bare soil, but it spreads uncontrollably, forming thick mats that smother native seedlings and ground flora. Even a tiny piece can regrow, making it extremely difficult to eradicate. It also harms native bush floors by preventing regeneration and depleting soil health.
4. Wild Ginger (Hedychium gardnerianum and H. flavescens)
Wild Ginger (Hedychium gardnerianum and H. flavescens) by Forest & Kim Starr, licensed under CC BY-SA 4.0.
With its tall stalks and lush tropical look, Wild Ginger is deceptively beautiful — but beneath the surface, it’s aggressively harmful. It spreads through underground rhizomes, forming dense clumps that crowd out native ferns and seedlings. It alters soil chemistry and blocks forest regeneration, making it one of the worst invaders in many regions of New Zealand.
5. Moth Plant (Araujia hortorum)
Moth Plant (Araujia hortorum) by Qumarchi, licensed under CC BY-SA 4.0
Also known as the “Cruel Plant,” this vine is toxic, aggressive, and dangerously sticky. Its milky sap can irritate the skin, and its seed pods are designed to disperse easily, helping it spread rapidly across fences, trees, and gardens. Worse, its sticky flowers can trap and kill beneficial insects and even small birds, earning it a notorious reputation among conservationists.
6. Japanese Honeysuckle (Lonicera japonica)
Japanese Honeysuckle (Lonicera japonica) by Aftabbanoori, licensed under CC BY-SA 4.0.
This fast-growing, twining vine might seem like a charming addition with its sweet-smelling flowers, but it poses a serious threat to New Zealand’s natural bush. Japanese Honeysuckle climbs and coils around trees and shrubs, forming dense tangles that shade out native vegetation. Once established, it dominates forest margins, outcompeting native vines and limiting biodiversity. Its ability to grow in a variety of conditions makes it a particularly resilient and invasive species across both urban and rural landscapes.
7. Blue Morning Glory (Ipomoea indica)
Blue Morning Glory (Ipomoea indica) by Moni Sertel, licensed under CC BY-SA 4.0
Known for its vibrant blue-purple flowers, Blue Morning Glory spreads through both seeds and creeping stems, making it incredibly hard to contain. It forms thick, smothering mats over trees, shrubs, fences, and even buildings. In natural areas, it overwhelms native vegetation, stopping sunlight from reaching ground-level plants and preventing natural regrowth. Its extensive root system and vigorous growth make it especially challenging to remove, and improper disposal can lead to rapid reinfestation.
How Jim’s Mowing NZ Can Help You Garden Responsibly
At Jim’s Mowing NZ, we’re not just about trimming lawns — we’re your local experts in efficient and reliable gardening services.
✅ We Identify and Remove Invasive Plants
Not sure what’s growing in your backyard? Our gardening teams are trained to identify common pest plants and can safely remove or contain them before they spread.
✅ We Offer Native Plant Recommendations
We’ll help you choose low-maintenance, native alternatives that thrive in your local conditions — boosting biodiversity and supporting native wildlife.
✅ Garden Cleanups & Planting Advice
Whether it’s clearing out an overgrown corner or starting a new garden bed, our team ensures you don’t accidentally plant something harmful to the environment.
✅ We Stay Up to Date With Regional Rules
Different councils have different banned plant lists. We know what’s allowed in your region and help you stay compliant — and environmentally responsible.
Protect New Zealand’s Natural Beauty — One Garden at a Time
Avoiding invasive plants isn’t just about keeping your garden tidy — it’s about protecting our native ecosystems, wildlife, and landscapes for future generations. By making smarter planting choices, you’re helping to preserve the unique biodiversity that makes Aotearoa so special.
At Jim’s Mowing NZ, we’re here to help you create a garden that’s not only beautiful, but also environmentally responsible. 📞 Call us at 0800 454 654 to book a service today.
Together, let’s grow better gardens — and a greener future.
Frequently Asked Questions (FAQ)
What defines an invasive plant, and why are they so dangerous in New Zealand?
Invasive plants are non-native species that lack natural predators in New Zealand, allowing them to grow aggressively, monopolise light and nutrients, and quickly dominate the landscape, thus disrupting native habitats and reducing biodiversity.
Which invasive vine is known for strangling native trees? Old Man’s Beard
(Clematis vitalba) is a rapidly growing climbing vine that blankets trees and shrubs, preventing light from reaching the plants below and effectively strangling and killing the native species.
Why is Moth Plant considered dangerous to local wildlife?
Also known as the “Cruel Plant,” the Moth Plant (Araujia hortorum) is a toxic vine whose sticky flowers can trap and kill beneficial insects and even small birds, earning it a notorious reputation among conservationists.
What specific risk do plants like gorse and pampas grass pose?
Some invasive plants, like gorse and pampas grass, are highly flammable and increase the risk of wildfires. Others can also increase erosion risks by replacing deep-rooted native plants with shallow-rooted invaders.
