Washington State Poisonous Plants

If you enjoy spending time outdoors in Washington state, knowing about the local poisonous plants is essential for your safety. This guide covers the key washington state poisonous plants you should recognize, helping you avoid dangerous native species in your garden or on the trail.

Many beautiful native plants have developed potent defenses. Learning to identify them is the first step to coexisting safely. Let’s look at the most important ones to watch for.

This list focuses on native species that pose significant risks through skin contact or if ingested. Always supervise children and pets around unfamiliar vegetation.

1. Western Water Hemlock (Cicuta douglasii)

Often called the most violently toxic plant in North America. It thrives in wet areas like marshes and stream banks.

Identification: Grows 3-6 feet tall. Has smooth, hollow stems with purple streaks. Leaves are toothed and lance-shaped. Small white flowers form in umbrella-like clusters.
Danger: All parts are poisonous, especially the roots. Ingesting even a small amount can cause violent seizures and rapid death.
Similar Safe Plant: It’s sometimes mistaken for edible plants like wild carrot or parsnip. Check for the purple-streaked, hollow stems.

2. Poison Hemlock (Conium maculatum)

This is a non-native but widespread and extremely dangerous plant found along roadsides and ditches. It’s important to include because it’s so common.

Identification: Can reach 10 feet tall. Recognizable by its hairless, purple-spotted stems. Leaves are fern-like. Flowers are small and white, arranged in umbrella clusters.
Danger: All parts are toxic. Ingestion affects the nervous system and can be fatal. It can also be absorbed through the skin for some people.

3. Western Poison Ivy (Toxicodendron rydbergii)

Found mainly in eastern Washington, this plant causes an itchy allergic reaction for most people.

Identification: Grows as a low shrub or ground cover. Remember “Leaves of three, let it be.” Leaves are shiny, with pointed tips and slightly notched edges. Berries are white or gray.
Danger: The oil (urushiol) causes a blistering, itchy rash upon contact. The oil can stick to clothing and pet fur, causing indirect exposure.

What to Do If You Touch Poison Ivy

Wash the area immediately with cool water and soap (like dish soap) to remove the oil.
Scrub under your fingernails.
Wash all clothing and gear that may have touched the plant.
Use calamine lotion or hydrocortisone cream to manage itching. See a doctor for severe reactions.

4. Stinging Nettle (Urtica dioica)

While not deadly, this plant delivers a painful surprise. It’s common in moist, shaded areas.

Identification: Grows 3-7 feet tall. Has opposite, heart-shaped leaves with serrated edges. The stems and leaves are covered with tiny, hollow stinging hairs.
Danger: Brushing against it injects chemicals that cause a burning, stinging sensation and raised welts that can last for hours.

5. Death Camas (Toxicoscordion venenosum)

This plant is deceptively pretty and often grows in the same meadows as edible camas, a traditional food source.

Identification: Grass-like leaves grow from the base. A central stalk holds clusters of creamy white flowers. The bulb looks like an onion but has no onion smell.
Danger: All parts are toxic, especially the bulb. Ingestion leads to severe vomiting, weakness, and potentially death. Never forage bulbs unless you are an expert.

6. Foxglove (Digitalis purpurea)

This popular garden plant is also a native naturalized species. It’s beautiful but contains powerful heart medicine.

Identification: Tall spikes (2-5 feet) with tubular, bell-shaped flowers in pink, purple, or white. Leaves are large, fuzzy, and form a rosette at the base.
Danger: Eating any part can cause nausea, vomiting, hallucinations, and heart problems. Even handling the plant can sometimes cause a rash.

7. Baneberry (Actaea rubra)

A shady forest plant with striking, but toxic, berries.

Identification: Grows 1-2 feet tall. Has compound, toothed leaves. Produces fluffy white flowers in spring. Bright red or white berries appear in mid-summer on thick, red stalks.
Danger: The berries are the most toxic part, especially attractive to children. Few berries can cause dizziness, stomach cramps, and headache.

Safety Tips for Gardeners and Hikers

You can enjoy Washington’s flora safely with a few simple habbits.

Before You Go Out

Learn the top 5 poisonous plants in your specific region. Use a reliable field guide.
Dress appropriately: wear long pants, long sleeves, and closed-toe shoes in areas with dense vegetation.
Consider carrying a plant identification app, but don’t rely on it solely for edibility.

While You’re Outside

Teach children the “Leaves of three, let it be” rule and not to put any plants in their mouth.
Stay on maintained trails to minimize contact.
Keep pets on leash to prevent them from brushing against or eating unknown plants.

If You Suspect Poisoning

Do not panic. Remove any plant material from the mouth.
Rinse the mouth with water.
Call the Washington Poison Center at 1-800-222-1222 immediately. They provide free, expert advice 24/7.
Do not induce vomiting unless a poison control expert tells you to.
If the person collapses, has seizures, or has trouble breathing, call 911 right away.

Landscaping with Native Plants Safely

You can still cultivate a beautiful native garden. The key is informed placement and management.

Know what you plant. Research any native plant before adding it to your garden, especially if you have kids or pets.
Create zones. Place known toxic plants in areas away from play spaces and edible gardens. Use fencing or decorative borders as barriers.
Remove high-risk plants. Consider removing plants like foxglove or poison ivy if the risk is to great for your household.
Wear gloves. Always wear gloves and protective clothing when handling or removing potentially irritating plants.

Frequently Asked Questions (FAQ)

What are the most common poisonous plants in Washington?

The most common dangerous native species include Western Water Hemlock, Poison Hemlock, Western Poison Ivy, and Stinging Nettle. Death Camas is also a major concern for foragers.

Are there any poisonous berries in Washington state?

Yes. Baneberry has highly toxic red or white berries. Other dangerous berries include those from Poison Ivy and the nightshade family. Never eat wild berries unless you are 100% certain of their identity.

How can I tell the difference between edible camas and death camas?

This is crucial. Edible camas (Camassia quamash) has blue flowers. Death Camas has creamy white flowers. The bulbs are similar, but Death Camas bulbs lack the onion-like smell of wild onions. When in doubt, do not dig or eat.

What should I do if my dog eats a poisonous plant?

Contact your veterinarian or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Try to identify the plant and note how much your dog may have consumed. Quick action is vital.

Can you get a rash from touching foxglove?

Some people can develop skin irritation from handling foxglove leaves. It’s a good idea to wear gloves when gardening around them, especially if you have sensitive skin.

Respecting these plants is part of appreciating Washington’s incredible natural beauty. By learning to identify these key species, you protect yourself, your family, and your pets. Always err on the side of caution, and when you’re unsure, simply admire a plant’s beauty without touching. Keep the poison control number (1-800-222-1222) in your phone—it’s a resource every Washington outdoor enthusiast should have.