Poison Hemlock: Lovely and Lethal

Deadly poison hemlock is so beautiful it might tempt you to tolerate it on your property. Its fern-like leaves and delicate white flowers are similar to those of Queen Anne's lace, a plant I've never seen except in books. Its leaves also slightly resemble those of wild carrot, parsley, parsnip, and fennel. That's another reason you don't want it near your garden. It just might cross pollinate with edible plants and cause problems. Experts I've talked to won't commit themselves on these effects one way or another.

All parts of this plant are poisonous. Consuming even a small amount of any part of the plant can be fatal. This is why you must make every effort to eradicate it from your yard if you have any children around who might be tempted to put it in their mouths. The best time to get rid of it is when it's very small and the ground is soft after a rain. It's taproot is long and if you grab the top to pull, the top will often separate, leaving the root in the ground. I tried pulling a bunch of them yesterday under such ideal pulling conditions, and only managed to get the root on one of them. I probably need to go back and use a fork spade to get the roots. When you finally get them from the ground, you will want to bag them up and throw them away. Do not compost them with the other weeds. When you finish weeding, remember to wash your hands thoroughly with soap -- even under the nails. Of course, if you're smart, you'll wear gloves. I was just impulsive and didn't want to go back after them.

Through the rest of this hub I'll be showing you lots of pictures of poison hemlock so that you will be able to identify it during any season. The rule of thumb is, if you're not sure what a plant is, don't take chances. You'll never be killed by leaving a plant alone.

Although poison hemlock seeds can travel, you will find most of them near where poison hemlock bloomed and died the year before. Poison hemlock is a biennial plant. The seeds germinate the first year. The second year the flowers grow and go to seed. Then the plants die in the heat of the summer -- at least that's been my experience.

If you walk around my county in autumn, you will often see forests of dead hemlock. After the rains come, you will see the ground turn green under these forests. The frilly leaves that emerge indicate poison hemlock. You might also see some seedlings with white veins in their spiny edged leaves. Those would be milk thistle, which often grows in close proximity to poison hemlock. Just as the plants are often found growing together, so do their seedlings.

I will show you a lot of pictures of the seedlings, some mixed with those of other plants as they occur in nature. I will identify what I can. You will notice that the smallest seedlings greatly resemble parsley. I always buy a parsley seedling and keep it in a pot, since I know then where the parsley is supposed to be. I think I have enough experience to know the difference now between the two, and, of course, the differences become more evident as the plants grow older. One big difference is that poison hemlock seems to germinate easier than parsley, and my lack of success at growing parsley from seed is the real reason I buy the seedlings.

You will notice that I took a lot of these pictures at Lawrence Moore Park in Paso Robles, California, which is adjacent to the Salinas River Trail. It is a riparian habitat and an oak woodlands. Poison hemlock thrives in either environment, but it will also do very well in your garden or open fields if it gets established during the rainy season. They seem to make no effort to eradicate this plant. It also grows anywhere the other weeds do, so you'd best learn to recognize it and help your children to the same, since they will find it growing nearly anywhere in wild areas of public land -- even if they are city parks.

Please remember that you can make even the largest pictures bigger by clicking them to see full size. You can observe the details more easily that way.

Poison hemlock stems are hollow. Because of this, boys have passed dead forests such as those above and decided to make whistles or flutes from the hollow stems. They died. The poison remains in the dead stems. It only takes a little bit to kill.

I hope by now you know poison hemlock well enough to leave it alone. It would also not be a good idea to sit on that park bench when the the hemlock is blooming, since some people react to its pollen. All parts of the plant are poison, and that would include the pollen, I think, if you breathe it in. I try to keep my distance when it's blooming.

You have probably noticed poison hemlock likes to be around milk thistle if you looked at the pictures just above this. You can read more about milk thistle in my related hub. It will also give you some additional pictures of the two friends together when in bloom. May you remain happy and healthy in the outdoors by keeping your distance from both these plants.