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Invasive Species & Harmful Plants Guide

The Adirondack Region offer numerous trails, waterways and wilderness areas to explore! In order to maintain the current ecosystem, we all have an important role to play. This guide is designed to help you identify invasive species that can have harmful effects on native fauna and flora and learn what you can do to help! We also highlight some nuisance plants you may want to avoid for your own safety.

While you're out hiking, biking, or waterfall hunting, please remember to be aware of your surroundings and take caution around harmful plants, knowing some can cause mild to severe reactions. Before boating or paddling, learn about simple measures you can take to make sure you don't introduce aquatic invasive species into Adirondack waterways.

See below for more information on invasive species and harmful plants you may encounter while out and about in the Adirondacks.

Harmful Plants

Giant Hogweed

Giant Hogweed is rare in the ADKs, and we can all do our part to keep it that way. It has a highly powerful sap that can cause very severe skin irritation and even blindness.

Wild Parsnip

Sometimes referred to as Poison Parsnip, Wild Parsnip sap contains photochemicals that cause irritation and painful burns, much like as its cousin, the Giant Hogweed.

Stinging Nettle

Stinging Nettle is an herb that may have health benefits when dried and prepared as a tea, but is irritating to the skin as a fresh plant. Learn how to recognize this nuisance plant.

Poison Sumac

With smooth green leaves and red, woody stems, learn why Poison Sumac is to be avoided if you come across it in the North Country.

Photo Credit: Joshua Mayer: Poison Sumac (Toxicodendron vermix) (license)

Poison Ivy

Be on the lookout for this highly irritating plant, growing low to the ground in many areas throughout the Adirondacks.

Harmful Algal Blooms

If a body of water looks discolored or covered in thick algae, it's very possible that a harmful algal bloom has taken over.

Invasive Insects

Gypsy Moth

Gypsy Moths are an invasive species that cause widespread defoliation while it is a caterpillar. The insects feed on a variety of trees including oak, maple, and birch.

Emerald Ash Borer

The Emerald Ash Borer is an invasive insect that damges and kills North American Ash trees. The small beetle is highly destructive and can be transported in firewood.

Hemlock Woolly Adelgid

A threat to the hemlock trees of the Adirondacks, the Hemlock Woolly Adelgid is a most recognizable for its white "wool" sacs.

Check out our wildlife guide for identifying any critters you may see along your travels as well »