State occurrence information for Giant Hogweed - Ask Extension
I'd like to know why there is no specific locality information on the occurrence of this species in Maryland on your extension page about this species...
Knowledgebase
State occurrence information for Giant Hogweed #868305
Asked May 13, 2024, 9:14 PM EDT
I'd like to know why there is no specific locality information on the occurrence of this species in Maryland on your extension page about this species. Additional site-specific info would help the public be better informed as to where they might confront this species in MD. You have a picture of the plant from Connecticut, why not occurrences in MD. There can always be slight distributional differences.
Further, there are occurrences listed for Md on the biodiversity site but none of the maps work and there is no info beyond county location. Depending on where this has been found in the State, that info could help the public be more informed local occurrences.
Howard County Maryland
Expert Response
Since Extension is not a regulatory agency, the Maryland Department of Agriculture (MDA) regulates and monitors occurrences of Giant Hogweed. The most recent information we found about its management is from their 2022 report (on page 39):
"The weed control program monitors infestations of giant hogweed (Heracleum mantegazzianum), a federal noxious weed, that was first detected in Maryland in 2003. It exists on sites in Baltimore, Harford and Garrett counties. In 2020, two sites were treated in Garrett County and two sites were treated in Baltimore County. County weed control programs provided spray crews and materials to treat these giant hogweed infestations. Eradication is a multi‐year effort and the weed control program treats infestations at the landowners’ expense."
The only occurrences in Maryland that are "research-grade" observations on iNaturalist (that is, the plant ID is verified as accurate) appear to be in the Towson area. Another map pin is currently present in the Columbia area, but after an apparent confirmation of the ID from an invasive plant specialist, the plant is said to no longer be in the area, so was presumably removed from that property.
As for the malfunction on the Maryland Biodiversity Project map, you may want to reach out to them to inquire about the glitch. Normally, you should be able to click on the "view quad details" link below the map of county occurrences to view more specific regions (quads) where an observation was made, though we realize that feature doesn't seem to be functioning properly on that species page. MBP also pulls some of their data from iNaturalist observations.
Miri
"The weed control program monitors infestations of giant hogweed (Heracleum mantegazzianum), a federal noxious weed, that was first detected in Maryland in 2003. It exists on sites in Baltimore, Harford and Garrett counties. In 2020, two sites were treated in Garrett County and two sites were treated in Baltimore County. County weed control programs provided spray crews and materials to treat these giant hogweed infestations. Eradication is a multi‐year effort and the weed control program treats infestations at the landowners’ expense."
The only occurrences in Maryland that are "research-grade" observations on iNaturalist (that is, the plant ID is verified as accurate) appear to be in the Towson area. Another map pin is currently present in the Columbia area, but after an apparent confirmation of the ID from an invasive plant specialist, the plant is said to no longer be in the area, so was presumably removed from that property.
As for the malfunction on the Maryland Biodiversity Project map, you may want to reach out to them to inquire about the glitch. Normally, you should be able to click on the "view quad details" link below the map of county occurrences to view more specific regions (quads) where an observation was made, though we realize that feature doesn't seem to be functioning properly on that species page. MBP also pulls some of their data from iNaturalist observations.
Miri
