It's pretty, ferny, green and lush, but very deadly! Poison hemlock grows prolifically all around the Midwest. If only a small size is ingested it can kill you in just one hour. So why am I including this in my medicinal herb posts? Because you need to get to know this bad boy.
Seriously, people mix it up all the time with beneficial plants such as yarrow, elderberry flowers, and Queen Anne's lace. Study the difference, learn your enemies.
Some things to know about comparing it to yarrow:
Yarrow doesn't ever grow over 2-3 feet - poison hemlock grows over 6 feet (12 feet in the perfect growing condition).
By the time yarrow blooms (late May here), most poison hemlock is already finishing it's life cycle.
Poison hemlock has a very different stem: it's mottled, hollow, and smooth.
Yarrow has a smaller, dense, and hairy stem. Also, yarrow smells bad, in my opinion.
Things to watch out for:
If you're using a weed trimmer on poison hemlock, wear protection for eyes and mouth.
It is preferable to dig the plant to remove it and destroy it. You can do this by hacking it with your shovel (using face protection and gloves), then remove it into a ditch or a remote location. It is still poisonous when dry and burning is not the best option unless you and everyone around wear protection or leave the area completely.
I found a little baby patch in my garden this morning. I hacked at it until it was obliterated, put the plant materials into a bucket, then put cardboard on what was left in the soil to make sure it didn't regenerate. I disposed of the bucket contents in a ditch at the back of the farm.
Study these pictures of each stage, learn the leaf structure, note the time of year, and look closely at the stem. Then you can safely avoid harvesting the wrong plant.