Cow Parsnip vs Giant Hogweed: 5 Key Differences

Written by August Croft
Updated: September 21, 2023
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Strikingly similar in their appearances and relation to one another, are there any real differences between cow parsnip vs giant hogweed? These two wild plants are considered invasive in a number of locations around the world, but what else do these plants have in common, and how can you learn how to tell them apart? 

In this article, we will compare and contrast cow parsnip with giant hogweed so that you can fully understand the differences between them. We will give you some tips on how to best identify them in the wild, as well as what they are typically used for. Finally, we will tell you where these plants both originated and where they are most likely to be found. Let’s get started now! 

Comparing Cow Parsnip vs Giant Hogweed

Cow Parsnip vs Giant Hogweed
Cow parsnip and giant hogweed belong to the same plant family and genus, but they are two distinct species from one another.
Cow ParsnipGiant Hogweed
Plant ClassificationHeracleum maximumHeracleum mantegazzianum
DescriptionReaches no larger than 10 feet tall with bright green stems and large umbel flowers. Flowers are white, large, and flattened on the top. Stems are hairy and green, with many large and simple leaves attached, similar to maple leaves. Sap from the plant can cause skin irritation and burns.Reaches up to 20 feet tall with green stems covered in purplish spots. Flowers are white and large, forming curved umbels at the top of each stem. Leaves are serrated at the edges and have deep veining throughout, with some fine hairs attached. Sap from the plant can cause skin irritation and burns.
UsesThe stems were commonly eaten by Native Americans, but only after the outer skin was peeled; otherwise slightly invasive and considered a weed. Some medicinal benefits, but not extensively studiedOriginally prized as an ornamental plant in Europe, before realizing how invasive it is. Now considered a noxious weed in most locations around the world
Origin and Growing PreferencesNative to North America; thrives in multiple sunny spots and frequently disturbed locationsNative to Russia; thrives in full sun and along sources of water, such as riverbanks and coastlines
Best Ways to IdentifyNo purple spots, flowers are flat, and the leaves are simple!Stems are very thick and large, with purple spots or blotches covering them!

Key Differences Between Cow Parsnip vs Giant Hogweed

Cow Parsnip vs Giant Hogweed

Like the name suggests, giant hogweed can reach 20 feet in height, while cow parsnip reaches up to 10 feet in height. 

©iStock.com/Mieszko9

There are a number of key differences between cow parsnip and giant hogweed. For example, cow parsnip and giant hogweed belong to the same plant family and genus, but they are two distinct species from one another. In addition to this, giant hogweed grows much taller than cow parsnip does. The stems of giant hogweed have purple spots on them, while cow parsnip stems remain green. Finally, cow parsnip is native to North America, while giant hogweed is native to Russia. 

Let’s go over all of these differences in more detail now. 

Cow Parsnip vs Giant Hogweed: Classification

It’s obvious that cow parsnip and giant hogweed are related to one another, given just how similar they look. However, despite giant hogweed and cow parsnip belonging to the same plant family and genus, they are classified as two distinct species from one another. Looking at them in more detail, cow parsnip is classified as Heracleum maximum, while giant hogweed is classified as Heracleum mantegazzianum

Cow Parsnip vs Giant Hogweed: Description

Cow Parsnip vs Giant Hogweed

The stems of the giant hogweed plant have distinct purple or red spots on them, while cow parsnip stems remain green.

©iStock.com/hapelena

You are unlikely to run across both cow parsnip and giant hogweed in the same area, but you would be hard-pressed to tell them apart if you did. However, there are few signs that you can look out for in order to tell which plant is a cow parsnip and which plant is a giant hogweed. For example, like the name suggests, giant hogweed can reach 20 feet in height, while cow parsnip reaches up to 10 feet in height. 

Both cow parsnip and giant hogweed have white umbel flowers, growing large and rounded at the top of each stem. However, cow parsnip flowers are flatter compared to the rounded flowers found on giant hogweed. The stems of the giant hogweed plant have distinct purple or red spots on them, while cow parsnip stems remain green. Finally, the leaves of the giant hogweed plant are more serrated and deeply veined compared to the comparatively plain leaves found on cow parsnip. 

Cow Parsnip vs Giant Hogweed: Uses

Cow Parsnip vs Giant Hogweed

With the skin peeled, cow parsnip stems were once consumed by Native Americans, while giant hogweed was once considered an ornamental plant.

©iStock.com/SailsKool

Cow parsnip and giant hogweed have very few uses nowadays, considering they are both noxious and invasive weeds in most locations. However, cow parsnip stems were once consumed by Native Americans, while giant hogweed was once considered an ornamental plant. Despite their original intentions, both cow parsnip and giant hogweed have very few uses in a garden or backyard, especially when you consider the fact that they both have the potential to overtake anything else you are trying to grow! 

Cow Parsnip vs Giant Hogweed: Origin and How to Grow

The origins of cow parsnip and giant hogweed differ from each other greatly. For example, cow parsnip originated in North America, while giant hogweed originated in Russia before being brought over to Europe as an ornamental plant. Both of these weeds grow with ease and similarly to each other, preferring full sunlight and locations near reliable sources of water. It is not recommended that you plant either of these two plants, given their noxious nature and ability to overtake other plants. 

Cow Parsnip vs Giant Hogweed: Best Ways to Identify

Cow Parsnip vs Giant Hogweed

When it comes to identifying cow parsnip, the flowers are flat and the stems are green, compared to the rounded flowers and purplish stems found on the giant hogweed plant.

©iStock.com/Svetlana Popova

Given that both of these plants produce a toxic sap that can cause skin abrasions and burns, it is important that you know how to best identify them in the wild. When it comes to identifying cow parsnip, the flowers are flat and the stems are green, compared to the rounded flowers and purplish stems found on the giant hogweed plant. Unless you are foraging for one of these plants in particular, it’s best to give anything that resembles cow parsnip or giant hogweed a wide berth, given the fact that many of the plants found in this plant family are toxic!

Should I Remove Cow Parsnip?

To prevent seed development and regrowth of plants, it is recommended to uproot and remove them.

For better control, it’s advisable to break the taproot using a shovel or spade. When dealing with extensive wild parsnip infestations, the most successful approach so far has been herbicide spraying. Optimal periods for herbicide application are during the spring, early summer, and once more in the fall.

Further, when working in proximity to wild parsnip, it is essential to wear protective gear, including gloves, long-sleeved shirts, pants, boots, and eye protection, to avoid direct skin contact with the sap.

The photo featured at the top of this post is © iStock.com/Svetlana Popova


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About the Author

August Croft is a writer at A-Z Animals where their primary focus is on astrology, symbolism, and gardening. August has been writing a variety of content for over 4 years and holds a Bachelor of Fine Arts Degree in Theater from Southern Oregon University, which they earned in 2014. They are currently working toward a professional certification in astrology and chart reading. A resident of Oregon, August enjoys playwriting, craft beer, and cooking seasonal recipes for their friends and high school sweetheart.

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Sources
  1. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C38&q=cow+parsnip&btnG=#:~:text=Cowparsnip%20(Heracleum%20lanatum%20Michx.)%3A%20An%20Indigenous%20Vegetable%20of%20Native%20People%20of%20Northwestern%20North%20America, Available here: http://www.weedinfo.ca/media/pdf/cow_parsnip_review.pdf
  2. The Giant Hogweed Best Practice Manual. Guidelines for the management and control of an invasive weed in Europe, Available here: https://www.researchgate.net/profile/Arvind-Singh-21/post/Giant_hogweed-how_to_reduce_or_eliminate_this_invasive_plant/attachment/59d639a179197b8077996d63/AS%3A402798261882880%401473045997989/download/1.pdf