Invasive species and floristry

Some varieties of plants used in floral design are a problem for the environment and can cause a lot of harm if they spread.

Key messages

  • Plants that spread and cause harm to the environment may be recognised as an invasive pest plant or invasive weed by a local regulatory authority.
  • Different governing authorities have their own lists of invasive pest plants — what is considered a problem in one region, may not be the same somewhere else.
  • Everybody has a role to play in preventing the spread of invasive species. This includes government, industry and individuals.
  • Florists can play an important role in protecting their environment, economy and community by avoiding the use of invasive pest plants in floral design and keeping plant material out of the environment.

What are invasive pest plants/weeds?

A ‘weed’ usually refers to a plant growing where it is not wanted.

Invasive pest plants or invasive weeds are more than that — they can cause significant harm in different ways.

Invasive weeds have usually been introduced to an area outside their natural range, usually through human activity. Humans might move the plant into new areas intentionally or accidentally, or disturb the land in a way that makes it easy for seeds or fragments of an invasive pest plant to take hold. Once introduced, pest plants establish and spread very rapidly.

Depending on the type of plant, invasive weeds can cause a number of problems, including:

  • compete with native plants and animals in critically important ecosystems
  • threaten natural and cultural heritage sites
  • introduce pests and diseases
  • increase forest fire intensity or frequency
  • prevent animals from accessing water and shade
  • reduce the natural beauty and value of the land
  • cause injury, allergies, poisoning, and respiratory problems for humans and animals
  • clog waterways
  • increase expenses for farmers to manage invasive infestations
  • reduce crop and pasture production
  • impact the mental health of people trying to manage weeds
  • require increased use of herbicides to control infestations spreading

Invasive weed species vary from state to state and region to region. Learning about the plants that are of most concern in your area is an important step in stopping their spread.

How do florists come into it?

  • Via flower farmers who grow or harvest invasive species for sale.
  • Via wholesalers and florists who sell the plant because it is not officially ‘banned’ from sale or because they don’t know what it is.
  • Via florists who hand-pick or ‘forage’ for the variety, without knowing the variety is an environmental threat.
  • Through moving plants from an area where they are appropriate, to regions where they are invasive.

Unfortunately, the combination of social media, floristry trends and sharing of attractive images across the world have made this problem worse. What’s considered a safe variety to use in one place can be harmful in another.  The practice of copying designs without checking local issues with the varieties used can contribute to invasive species spreading.

How plants spread

Invasive weeds spread when propagules – parts of the plant that can become new plants – receive the right conditions for growth. For most plants, this is the seed. However, some varieties can strike new plant growth from a small branch cutting or just a fragment of the plant or root system.

Florists can spread plant material via customers who intentionally take it home. From there it can be accidentally introduced into gardens and beyond the garden fence when propagules escape the compost.

Floral designers can spread invasive pest plant material by taking the material into new zones (via wedding and events, for example) and through disposal methods that enable the propagatable material to spread.

Why aren’t all invasive plants banned from sale and use?

Most countries or regions have a list of plants that are banned from being imported or sold. However, this generally only includes the most widely harmful varieties for that area.

These species are often regulated once they have already caused an obvious impact in the environment. However, there are many more plant varieties that have the potential to cause a lot of harm if they do spread. Governmental regulation should not be relied on as the only tool to prevent spread.

Everybody has a role to play in helping to stop the spread of invasive plant species, including the individuals and businesses within different industries.

What can florists do?

Preventing the spread of invasive plants is the most effective method of controlling these species. Ensuring that we do not harvest or use any invasive species is one of the best things we can do as members of the flower industry.

You can prevent the spread of invasive species by:


  1. Learning about your locally and regionally invasive species.

Not all non-native plants are invasive, and some plants native to a particular country may even become invasive outside their normal range of distribution, so get to know which ornamentals are causing or might cause a negative impact. Your local municipal authority or a community group involved in weed management can help you learn about which species pose a problem in your region.


  1. Avoiding the use and promotion of invasive species

Stopping the problem from becoming worse is the most powerful thing you can do. Avoid using invasive species, particularly plant propagules. Likewise, avoid promoting designs or sharing images that feature known invasive species.


  1. Destroying all invasive plant material that can grow into new plants.

If you absolutely cannot find an alternative to an invasive plant species, then it is critical that you destroy and dispose of the plant material properly.  All plant material that can form new plants must be destroyed. This might include flowers, fruits, roots and underground tubers or rhizomes. It may also include cuttings of the plant that can take root from a section of the stem (such as ivy or willow).

Understanding the safest means of disposal requires knowledge of each specific plant and how the plant reproduces.  Therefore, the best recommendation for floral professionals is to double-bag the plant and put it into the landfill.

However, it is important to remember that using invasive species, and adding to landfill, both work against the Sustainable Floristry Network Design and Business Principles.


  1. Get an app for your phone to help with plant identification.

Identifying invasive species can be daunting.  Fortunately, there are some great apps available that can assist with plant identification.  Wild Spotter is an app used in the US in conjunction with the US Forest Service to help manage and track invasive species.  iNaturalist is another app that can be used worldwide to identify plants and is a is a joint initiative by the California Academy of Sciences and the National Geographic Society.  In Australia, the WeedScan website and smartphone app will be officially launched in June 2023.


  1. Share your new-found knowledge

See another floral designer using or promoting invasives? Quietly start a friendly, private conversation. They might not know that what they’re selling is having a harmful impact!

CASE STUDY – Pampas Grass

The trend

In recent years, pampas grass has become very popular as a feature in wedding designs and installations. This trend emerged alongside an increased interest in dried flower arrangements, which appeared as a response to the #nofloralfoam movement.  Florists turned to botanical materials that could last out of water for a long time. The response was completely understandable.


The plant

The problem with pampas is that it is a particularly invasive species in many countries across the globe.  Each seed head carries up to 100 000 seeds. The plant is such a problem that a leading global nature conservation agency has called for urgent action to address the issue. This includes restricting movement of the plant and removal programs to destroy the plants outside of its native South America.


The impact

Once in the environment, pampas grass establishes and spreads quicky. In the process it overtakes native plants, impacts biodiversity, creates fire hazards, creates homes for vermin and can impact our ability to protect the health of forests.

This document was created following a round table discussion initiated by Becky Feasby of Prairie Girl Flowers, CA, on the 12th of December 2022.  Twelve industry and education representatives from around the world were in attendance, with the goal of discussing some strategies to tackle the specific issue of invasive species in floristry.
This group was led by an expert panel that included Prof. Doug Tallamy, Entomology and Wildlife Ecology, University of Delaware, US; Latifa Pelletier-Ahmed, botanist and native plant expert, Calgary, Alberta, CA; and Nicola Dixon, State Priority Weeds Coordinator, Department of Primary Industries, NSW, AU.
This document was created by the Sustainable Floristry Network, with contributions and input from members of the group. The information contained within this document does not reflect the opinions or input of any one member of the group, but should be interpreted as a summary of some general best-practice guidelines around managing invasive plant species, as they apply to florists.