Prepare your water garden for winter responsibly - Part I

Do not release! Properly dispose of unwanted aquatic plants and animals to prevent introduction of aquatic invasive species into Michigan waterways.

Cooler autumn temperatures stimulate a host of cleanup tasks in gardens and landscapes. For water gardeners this means draining and preparing ornamental water features for sub-freezing temperatures – including the proper disposal of unwanted aquatic plants and animals. It is the responsibility of the water gardener to prevent the introduction of potentially invasive water garden plants and animals into Michigan lakes, streams, ditches or ponds.

Safe and proper disposal of plants and animals that you’ve purchased at a garden center early in the summer and nurtured all summer can be emotionally difficult. Caution and careful thought are needed in deciding what to do with unwanted plant and animal species. Releasing any aquatic organism into the environment is not an accepted practice and may even be punishable by law.

invasive water plants
European Frogbit (Hydrocharis morsus-ranae) is just one example of a prohibited plant.
Photo credit: Dave Brenner, Michigan Sea Grant

Many water garden plants and animals have the potential to become invasive – outcompeting and destroying the rich diversity of native aquatic species. Because they have evolved together, native plants and animals have a symbiotic relationship; they rely on each other for nutrients, sunlight and water and keep each other in balance so that one species does not dominate the environment.

When non-native plants or animals are introduced into waterways they can become invasive due to an absence of natural controls (predators, disease, climate, etc.) that would normally keep them in check. Exotic non-native plants and animals have proven over and over again their ability to adapt to colder environments and water temperatures. These non-native invaders of our waterways are called “aquatic invasive species” (AIS). They not only negatively impact the aquatic environment – they create negative recreational and economic impacts for individuals, businesses and communities.

What can water gardeners do to help prevent the spread of AIS? For starters, never assume a plant or animal is native to Michigan. Never assume a plant or animal is harmless or benign. Understand that retail names and descriptions of plants and animals can be misleading.

Disposal options include:

  • Contact retailer for proper handling advice or for possible returns
  • Give/trade with water gardener
  • Donate to a local aquarium society, school, or aquatic business
  • Seal aquatic plants in plastic bags and dispose in trash to be landfilled
  • Contact veterinarian or pet retailer for guidance about humane disposal of animals

Do not release water garden animals and plants into the outdoor environment – even if they appear to be dead.

Habitattitudeis a national education campaign encouraging proper disposal of exotic plants and animals to protect waterways from AIS. It is endorsed by Michigan State University Extension, Sea Grant Michigan and Michigan Lake and Stream Associations.

Read Part II of this series, Prepare your water garden for winter responsibly - Part II.

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