Learn / Ask The Landscape Professional
I'm wondering what this is. It's nothing I planted, which makes me suspicious, but we have so many glorious trees thanks to the squirrels, thought I'd check before pulling. Thank you! Sue
Hello Sue. What you have is definitely a weed. It is called Japanese Hop Vine (Humulus
japonicas) a member of the Hemp family. As can be seen in your picture, the leaves have
5 distinct lobes; when you touch them they are rough to the touch. This plant originated
in Asia and was imported into this country in the late 1800's for use as an ornamental vine
and tonic. Unfortunately, it is very invasive and it has become widespread throughout
the northeastern US. Japanese Hop likes fertile soil and sunlight; in the right conditions
it can grow rapidly - to 10 feet high and 35 feet wide in a year! If left unchecked, it
can form dense mats several feet thick. The good news is that in our region it is an
annual (dies every year in the cold weather) but regenerates from seeds it disperses the
previous year in the early fall. Seeds can remain viable for up to three years in the
soil, so the trick is to pull it when you see it and you'll eventually win the battle.
Use black plastic bags for disposal and put out with the trash to go to the incinerator.
Japanese Hop has a famous native cousin, the common hop (Humulus lupulus), that you may
also encounter. Common hop looks similar to Japanese Hop, except it is generally 3-lobed
and it is a non-invasive perennial. The female flower cones, called "hops", have been
used in beers for centuries for flavor and preservation.
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About Linda Lillie
Linda K. Lillie is the President of Sprigs & Twigs, Inc, the premier
landscape design and maintenance, tree care, lawn care, stonework, and carpentry
service provider in southeastern Connecticut since 1997. She is a graduate of
Connecticut College in Botany, a Connecticut Master Gardener and a national
award winning landscape designer for her landscape design and landscape installation work.