Horticultural businesses

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Learn more about invasive species and your business with this poster!

Plant nurseries and water garden stores play an important role in protecting Minnesota waters from aquatic invasive species.

Invasive species impact horticulture businesses. Invasive plants like yellow floating heart and invasive animals like mystery snails can grow rapidly, completely overtaking ponds and water gardens. Diseases can impact the health of pond plants and animals. Invasive species cause recreational, economic and ecological damage—changing how residents and visitors use and enjoy Minnesota waters.

Plant nurseries and water garden stores can unintentionally introduce aquatic invasive species (AIS). Unwanted seeds, eggs, larvae, small animals, and plant fragments can hide within purchases of desired plants or animals. Incorrect species might be sent to you by mistake. Sometimes plants and animals are released or escape into the environment during heavy rains and flooding events where they can suffer or cause environmental damage. 

Did you know? It is illegal to possess, import, purchase, transport, or introduce prohibited invasive species


To help protect Minnesota waters and comply with state law, here are some best practices to reduce your risk of introducing invasive species:

Ensure Your Business Does not Buy or Sell Prohibited Invasive Species

The following prohibited invasive plants and animals have been documented in the horticulture trade and are illegal to possess or sell in Minnesota.

Aquatic Plants

  • African elodea (Lagarosiphon major)
  • Common reed (Phragmites australis subsp. australis)
  • Curly-leaf pondweed (Potamogeton crispus)
  • Eurasian watermilfoil (Myriophyllum spicatum)
  • European frog-bit (Hydrocharis morsus-ranae)
  • Flowering rush (Butomus umbellatus)
  • Giant salvinia (Salvinia molesta)
  • Hydrilla (Hydrilla verticillata)
  • Purple loosestrife (Lythrum salicaria)
  • Yellow floating-heart (Nymphoides peltata)
  • Water soldier (Stratiotes aloides)
  • Water chestnut (Trapa natans)


  • Eastern mosquitofish (Gambusia holbrooki)
  • Eurasian minnow (Phoxinus phoxinus)
  • Golden freshwater clam (Corbicula fluminea)
  • Grass carp (Ctenopharyngodon idella)
  • Jumping worms (Amynthas and Metaphire spp.)
  • Red swamp crayfish (Procambarus clarkii)
  • Western mosquitofish (Gambusia affinis)

Additional species that are illegal to possess and sell include all Minnesota prohibited invasive species, state and federal noxious weeds and federally-listed injurious wildlife.

Before Making Purchases

Know the laws in Minnesota. Keep up to date on invasive species regulations.

  • It is illegal to possess, import, purchase, transport, or introduce prohibited invasive species.
  • You can possess, sell, buy, and transport regulated invasive species, but they may not be introduced into a free-living state, such as being released or planted in public waters.
  • It is illegal to place any non-native aquatic plant into public waters, or to plant them where they may accidentally spread to a public water.
  • Invasive species regulations differ between states. For example, yellow floating-heart (Nymphoides peltata) is commonly sold nationwide, but it is a prohibited invasive species in Minnesota.

Learn to recognize invasive species.

Purchase by species name, not common name, whenever possible.

  • Become familiar with the scientific names of organisms you’re interested in purchasing. Unlike common names, scientific names are unique to each species and do not change by region. For example, “Anacharis” is a commonly used name in stores Egeria densa (Brazilian waterweed), a prohibited species. Searching and ordering organisms through their scientific name will greatly reduce the chances of ordering AIS by mistake.
  • Not all businesses list organisms by their scientific name. It is better to order from businesses that list scientific names. If a scientific name is not listed, ask if it can be provided to you. If it cannot be provided to you, then it will be difficult to know if you are unintentionally buying AIS.

Checking Purchases

Once you receive your organisms:

  • Check to make sure you received the organisms you ordered and nothing else. Orders can get mixed up or mistakes can be made, especially if you are ordering online.
  • Inspect purchases for unexpected species such as eggs, larvae, leeches, snails, crayfish, seeds, plant fragments, etc. 
  • Rinse off hitchhikers, seal them in a plastic bag, and dispose in the trash.
  • Never keep, sell, or give away unexpected species or use them as food for other animals. Unidentified species could be invasive or carry disease.

Report prohibited invasive species received to the DNR: Rafael Contreras-Rangel, AIS in Commerce Prevention Planner, [email protected], 651-259-5350. Include pictures and the name of the supplier whenever possible.

Do not sell plants or animals classified as prohibited invasive species or noxious weeds.

Never release water garden plants or animals into the environment. It is illegal to release most non-native species.

Talking to Customers About AIS

Share information about what water gardeners can do to prevent the introduction of invasive species. Local businesses like you are trusted sources of information for proper water garden and pond care.

Remind customers to never release non-native species into the environment. It is illegal to introduce non-native species into a free-living state, such as from intentional release, planting or escape into public waters because they can harm the environment, recreation, and the economy.

Provide customers with these alternatives if they have a water garden plant or animal they can no longer care for:

  • Dispose of unwanted plants in a sealed plastic bag in the trash. Do not compost, because seeds and other reproductive parts may remain viable even after composting. Also consider:
    • Dumping rinse water on dry land.
    • Freezing all debris, packing materials and unwanted plants in a sealed plastic bag. This ensures the plants are dead before they are carried to landfills or other locations where living plants could still cause harm.
  • Contact a retailer for possible returns.
  • Find a surrender event near you to rehome your pet.
  • Give or trade with other hobbyists or a local hobbyist society.
  • Contact a veterinarian or pet retailer for guidance on humane disposal of animals.

Remind customers from out of state to check their state’s invasive species list before ordering, because invasive species regulations differ between states.

For information and guidance on what to do with a prohibited invasive animal, contact Rafael Contreras-Rangel, AIS in Commerce Prevention Planner, [email protected], 651-259-5350.

Learn More and Stay Connected

  • Learn about how to prevent the spread of invasive species while doing other activities on Minnesota waters.
  • Sign up for the DNR’s email list specifically for horticultural businesses to stay up-to-date on new information, resources, and changes in regulations related to invasive species.

Related Links

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