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Killing Weeds/Tree Roots, but wanting to replant in that Area #593010

Asked August 29, 2019, 12:28 PM EDT

Hi! I have 2 questions. #1. I had a Black Locust tree cut down before I bought my house in December 2016. The Stump was ground down slightly, however the root system is very extensive and large and has been sprouting ever since. I keep cleaning and cutting it down but it appears to be coming back even more aggressively sort of all over. I recently had the sprouts totally cut down and come of the roots removed but not the extremely large ones. NOW I must kill this root system. Can I use Epsom Salt, Vinegar, or any other natural thing or must I use some sort of herbicide? What do you recommend and do you have any instructions that I should follow or a website recommendation. #2 To follow up on this last question. I have some beds of tilled up soil that were covered in weeds and vines. Now it is just loose soil. I would like to Kill all weeds or grass that may have sprouted in the last week and also put on PREEN premerginet to kill any new seeds that may sprout. I want to buy existing plants to plant there then cover area in mulch. I just want MULCH and DESIRABLE PLANTS, not hundreds of vines and weeds. What do you suggest I do and can I use any natural items in this process as Dawn Dish soap, vinegar, or salt. Please advise and Many thanks! Karen

Jefferson County Kentucky

Expert Response

Question 1 - There is not a "natural" solution to killing tree roots that tend to send out shoots after the parent tree is cut down. Black locust are especially difficult to contain if the stump is not deeply and widely ground out. There are several chemicals that can help kill roots or hasten root and decay.

The University of Kentucky recommends:

"When trees are to be cut down, a cut stump herbicide treatment is recommended. This method involves spraying the freshly cut surface or stump with concentrated herbicide solution. It is important to treat the cut stump as soon as possible and no longer than one hour after the top of the stump is exposed to the air. As the top of the stump dries out and living cells in the outer portion of the stump die, the effectiveness of the treatment is reduced. If trees have already been cut, it might be possible to re-cut the stump within several weeks after the initial cut. Re-cut at least 2 inches below the original cut to expose moist live wood and apply the herbicide. However, delaying the treatment reduces the effectiveness.

Some commonly available herbicides in Kentucky that are labeled for cut stump application include products that contain: glyphosate (e.g., Roundup Ultra and Roundup Pro); triclopyr (e.g., Remedy and Garlon); dicamba (e.g., Banvel and Clarity). Other herbicides such as Crossbow, Tordon, and Pathway are also labeled for cut stump applications; however, these products have a greater potential to produce damage to adjacent crop and ornamental plants through volatilization and/or soil persistence of their active ingredients. Therefore, they are not recommended for use in areas directly adjacent to desirable plant species. In addition, Tordon and Pathway are noncropland herbicides that are not labeled for use in pastures or in fencerows adjacent to pastures.

Follow label directions for cut stump or stump surface applications.                      

Question 2 - Again, there are very few organic herbicides that won't damage your soil. The use of the products you mentioned are not labeled as herbicides so it is unwise to use them as such, so I can not recommend them. Online or In the organic chemical section of many garden centers or nurseries you may find an organic herbicide. Preen is an excellent pre-emergent for the plants listed for control on the label. If you hand pull, then use Preen and apply mulch weed control should be easy. That keeps use of heavy chemicals to a minimum.                            


Feel free to contact our office if you have other questions.

Let me know if I can help you further!


Carol Wilder
Horticulture Technician
Jefferson County Cooperative Extension Service
Email: <personal data hidden>

<personal data hidden>
200 Juneau Drive
Louisville KY 40243

                                                                  

An Ask Extension Expert Replied September 03, 2019, 9:04 AM EDT

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