Poison Hemlock vs.
Wild Carrot (Queen Anne's Lace)
Wild carrot (Daucus carota), also known as Queen Anne’s Lace, is often mistakenly identified as poison hemlock (Conium
maculatum), and it is more likely what is growing in your backyard. Both are weeds, but the control method may be
different once correctly identified.
Poison hemlock is in the same family (Apiaceae) as carrots, celery, parsnips, and several herbs, including parsley,
cilantro, chervil, fennel, anise, dill, and caraway.
Poison Hemlock vs. Wild Carrot
Stems (figure 1): The most distinct visible difference between
poison hemlock and wild carrot is the stems. The poison hemlock's
stem has purple blotches, is "hairless," and is hollow. Wild carrot's
stem is green (young plants), burgundy-green (mature plants), and
"hairy."
Foliage (figure 2): Although both species have fern-like leaves,
there are some differences in the leaves. The leaves of poison
hemlock are sharper in detail, up to 2 feet long, and glossy dark
green without "hairs." Wild carrot leaves are lacy or feathery,
shorter (2-6 inches long), and nearly hairless to bristly-haired.
Flowers (figure 3): The flowers of poison hemlock and wild carrot
are more similar. Both have white flowers clustered at the end of
the stem that are flat, umbrella-like.
Scent: When crushed, the leaves and stems of poison hemlock
have an unpleasant odor, whereas the leaves and stems of wild
carrot smell like carrots when crushed.
Habitat: Poison hemlock and wild carrot are considered invasive
plants found in fields, pastures, vegetable crops, orchards,
roadsides, and other disturbed places. Wild carrot is typically
found in sandy or gravelly soils, and poison hemlock prefers moist
soils.
Impact: Of course, there's a significant difference in the effect of
poison hemlock vs. wild carrot. Poison hemlock is toxic to livestock
and humans through ingestion. Cases of human poisoning are
relatively rare. The toxin affects the nervous system and can result
in fairly rapid death in livestock that feeds on poison hemlock in fresh foliage, stored silage, or contaminated hay. The
sap of poison hemlock can also cause contact dermatitis.
Page 1
Updated 10/2022 • Denton County Master Gardener Association (DCMGA)
Find more gardening information on dcmga.com
Management & Control
The management of both poison hemlock and wild carrot are similar.
• Inspect areas frequently for new infestations. Young plants of both species start as rosettes of foliage.
• Mechanical removal is preferred using a spade or trowel. Wear gloves and long sleeves to avoid skin exposure to
the sap of poison hemlock. Be sure to remove the entire taproot to prevent regrowth. Discard the plant in the
trash, do not compost or burn it.
• Mowing frequently before flowering begins or plowing or cultivating the area will disrupt the seed germination
cycle. Bag and discard the clippings to avoid inadvertently dispersing seeds.
• Use herbicides only as a spot treatment on seedlings or small rosettes. Mechanically remove mature plants.
Large infestations may be treated with herbicides containing active ingredients 2,4-D, triclopyr, or glyphosate.
Fully follow label instructions about protective clothing and treat carefully to avoid overspray. You can use an
empty six oz. can (from tomato paste, for example) with both ends removed to guard against overspray.
Learn more about poison hemlock and wild carrot from the links below.
Sources & Resources
"Poison Hemlock," University of California Agriculture & Natural Resources
http://ipm.ucanr.edu/PMG/PESTNOTES/pn74162.html
"Wild Carrot," University of California Agriculture & Natural Resources
http://ipm.ucanr.edu/PMG/WEEDS/wild_carrot.html
"The 'Don't Touch Me' Plants," Purdue University Extension
https://ag.purdue.edu/btny/purdueweedscience/wp-content/uploads/2021/03/The-Dont-Touch-Me-Plants.pdf
Page 2
Updated 10/2022 • Denton County Master Gardener Association (DCMGA)
Find more gardening information on dcmga.com
