no one can identify this spreading weed

tenuviel(MD)April 3, 2006

There are these reddish purple shoots coming up around my house, and at the edge of my yard. They kind of look like asparagus. They are in various stages of development, some are now about a foot tall and sending up more shoots, appears to be spreading. The stem is fleshy, not as much as a succulent, the leaves are more delicate, not hairy, alternate, rounded, and about 4 inches in diameter. They are a dark green veined with reddish purple, and slightly curled under. Upon digging the root system is extensive, growing laterally, and spreading at all levels of ground, down to 4 feet. The largest roots were almost 2 inches thick. The stalks left in winter are about 5 feet high, and are hollow and reed like ( this is not a reed though) This is my first year living here, so I do not know if it produces flowers yet. The soil is very sandy here. It appears very resilient, and is starting to come up through the cement. any ideas? help!

Thank you for reporting this comment. Undo
morz8(Washington Coast Z8b)

Japanese Knotweed? Description: New shoots asparagus-like and green to purple/red, fiberous roots, hollow stems.

Here is a link that might be useful:

    Bookmark   April 4, 2006 at 12:11AM
Thank you for reporting this comment. Undo

this is defidently it. Thank you. Any earth friendly way of controlling it?

    Bookmark   April 4, 2006 at 9:51PM
Thank you for reporting this comment. Undo
morz8(Washington Coast Z8b)

Happily, I haven't had to deal with knotweed personally...

but it doesn't sound good - this is one tough and invasive plant. Hopefully someone else (or your county extension agent) will have some suggestions for efficient long term removal, but it looks to me like you will be at this for a while and will need to use more than one method of control. Wish I had better news...


Large colonies of this species are extremely difficult to dig up due to their high rhizome densities. Digging of large colonies is not recommended as it is very labor intensive and unlikely that all below ground material can be removed. Small patches may be dug, however care should be used in removing plant material as improper disposal can spread the species further. Repetitive cutting or mowing within a single growing season to deplete stored reserves and remove photosynthetic tissue has been effective. Eradication of the rhizome system is necessary for control of this aggressive invasive species.


Herbicide has been generally effective at controlling this species. Repetitive cutting of stems with spot application of Roundup®, Accord® or Glypro® to the stumps, and foliar spraying in large populations has been reported to be successful.


There are currently no biological controls available for Japanese knotweed.

    Bookmark   April 5, 2006 at 1:16AM
Thank you for reporting this comment. Undo
kalmia10(z7 WA)

Glyphosate is effective at about a 3-5% rate in a foliar treatment. Don't waste your time spraying at this time of year though. We have found it works well to bend or cut the stems in June/July and come back in late summer/early fall and treat the shorter regrowth: not as much product used, less exposure and drift since the plants are shorter, and the translocation of the herbicide to the roots is best in fall. Not sure if this is suitable for your situation but it does work well. Good luck!

    Bookmark   April 7, 2006 at 5:57PM
Sign Up to comment
More Discussions
Weed Identification Kern River Valley, CA
Hoping some folks might be able (willing) to help me...
nexev - Zone 8b
Best organic solutions
Hello, Any advice on the best things to buy to address...
Neglected Yard
I moved into a house last winter and the yard seems...
Sponsored Products
Abetta Flex Gaited Round Skirt Saddle - 20536F6BK
$426.66 | Hayneedle
Powell Blue Shutter Console One Drawer Two Doors
Beyond Stores
Spot on Square | Roh Crib Conversion
Waverly Antique Brass One-Light Wall Sconce with Silken Parchment Shade
$62.00 | Bellacor
Zuo Modern Jasper Floor Lamp in Antique Black Gold
Beyond Stores
Dogit Rectangular Mattress Bed - D5151
$32.38 | Hayneedle
Freeport Oil Rubbed Bronze One-Light Large LED Outdoor Wall Light
$349.00 | Bellacor
Tamburo 16 Bronze Three-Light Drum Pendant with Marble Grigio Glass
$715.50 | Bellacor
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™