Invasive tuberous weed - Ask Extension
How do I get rid of this unwanted fast growing weed that is taking over my gardens. It has a deep tap root, very hard to dig out even when it is small...
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Invasive tuberous weed #638915
Asked May 21, 2020, 1:02 PM EDT
How do I get rid of this unwanted fast growing weed that is taking over my gardens. It has a deep tap root, very hard to dig out even when it is small. And it grows to over six feet by Fall. There are dozens of these plants popping up. I am over whelmed with trying to dig them all out.
Harford County Maryland
Expert Response
This is pokeweed, and it does grow a huge tuberous root what stores so much energy that it is able to grow back if you do not get it all.
Here is our page about it:
https://extension.umd.edu/hgic/topics/pokeweed
You can also try exhausting the root by cutting it back to ground repeatedly during the growing season.
Do not let its green leaves survive for long. They are replenishing the stored energy in the roots.
Become familiar with the seedlings of this plant and pull when they are only a couple of inches. Pull when soil is moist so you can get the whole root before it gets established.
A systemic herbicide containing glyphosate that goes down to kill the roots can be effective. Apply to foliage in late summer so it will be pulled down into the roots better. You can use less herbicide if you cut down the plant and apply to the top of the tuber to get the herbicide closer to the root. Digging down and cutting a big wound in the tuber (slicing off the top), then spraying the wound, has been very effective with one application.
Glyphosate is a total vegetation killer. Do not let it contact your desirable plants. Also, do not use in a vegetable garden.
Ellen
Here is our page about it:
https://extension.umd.edu/hgic/topics/pokeweed
You can also try exhausting the root by cutting it back to ground repeatedly during the growing season.
Do not let its green leaves survive for long. They are replenishing the stored energy in the roots.
Become familiar with the seedlings of this plant and pull when they are only a couple of inches. Pull when soil is moist so you can get the whole root before it gets established.
A systemic herbicide containing glyphosate that goes down to kill the roots can be effective. Apply to foliage in late summer so it will be pulled down into the roots better. You can use less herbicide if you cut down the plant and apply to the top of the tuber to get the herbicide closer to the root. Digging down and cutting a big wound in the tuber (slicing off the top), then spraying the wound, has been very effective with one application.
Glyphosate is a total vegetation killer. Do not let it contact your desirable plants. Also, do not use in a vegetable garden.
Ellen
