Giant Hogweed

Skin contact with the juice followed by exposure to the sun can cause permanent scarring. Sap in the eyes can cause blindness. Just brush...Read Moreing against the hairs can cause dermatitis. There are also many documented reports of injuries to animals.

This plant isn't just a hazard to people and animals, but also an invasive threat to natural habitat. 13 states have independently banned this as a noxious weed, and the United States federal government has made its cultivation illegal throughout the US. The US has taken the extra step and made it mandatory to report any infestation to the USDA/APHIS.

Heracleum persicum is a different species and not a synonym, though it too is a threat to natural habitat in a wide range of climates, and Norway has a program to fight its spread.

If you live in N. America and want to grow this species, consider growing cow-parsley (H. maximum) instead. This is a big bold biennial that's closely related to giant hogweed and looks very similar. It too can cause photodermatitis, and it too self-sows aggressively, but it's native to most of N. America and not a threat to its ecology.

My friend had this in her garden we prized it until we found out what it was, the ministry of natural resourses is removing it soon we we...Read Morere told not to remove it ourselves because of the dangers of the sap

I love this plant...it doesn't spread, grows slowly, and looks alien. Thus being said - I grow this plant on purpose, and I enjoy it. M...Read Moreost everything you hear about this plant is a lie, except for the phototoxicity, and even that is greatly exaggerated. Poison ivy is many times more dangerous than this plant.

If people are having problems with this plant, it's because they lack the ability to talk to their children about the various dangers of the world. While it might be difficult to teach your children about how to identify poison ivy, Giant Hogweed looks like it fell from space...like something from another world; once you've seen it, you'll never forget it, and neither will your children.

If you grow monkshood/wolfsbane, castor beans, oleander, fox glove, rosary peas, etc, and you haven't grown Giant Hogweed because its "dangerous"...then there is something amiss in the world. I could name 1000 plants that will kill a human in seconds, and Giant Hogweed is at the bottom of that list, and it's not even invasive.

While this plant may be on the Federal Weed list, perhaps it's because 6 of the most important new medical compounds (drugs) in the world are being synthesized from this plant.

The stems are green with reddish speckling, but hard to confuse with similar plants on account of its size. In the UK this plant is far...Read More less common than the much smaller regular hogweed. I found a large clump of this growing on a former dumping ground for green waste, now derelict & overgrown. The large leaves create deep shade below in which almost nothing grows. Plants growing in shade are smaller than those in sunny positions.
Where clumps grow they die off in autumn,leaving behind messy looking bare patches in winter, littered with dead stalks and pitted with holes where the stems of the previous years plants grew. This plant never seems to grow in balance with surrounding vegetation, it tends to completely take over the places that it invades.