Roundup to kill weeds?

Question

I'm trying to totally clear a part of my yard that is under a tree. The ground is covered with weeds and is basically a thick weed wasteland right now. If I put down roundup to kill the weeds and everything else, how long will it before I can get anything else to grow in that area? Will it also kill the tree?

Answer 1

Roundup is basically inert within a few days. It kills whatever you spray it on, then it turns itself off. I don't know the exact time frame, but you can look on the back of the roundup bottle. It will not kill the tree, because it kills by being absorbed through the foliage. As long as you don't spray it on the tree directly (i.e. the leaves, branches, trunk), then your tree will be fine. Even when the round up gets washed into the dirt.

If you have more time, then I would recomend using some other method to kill all the weeds. Put down a few (5 or more) layers of newspaper, or some cardboard that hasn't been printed on. The newspaper is good because it's ink is soy based (most newspapers use soy based ink, you can check with the individual newspaper to make sure). Use only the regular black and white pages, NOT the color ads. So put down the newspaper, then wet it down with a hose. Put compost over it, and wait a few weeks. Technically, you don't have to wait to plant, but a few of the weeds are going to breach the newspaper barrier regardless, and more will breach it when whatever plant you put in sends roots down through the paper. You can make sure you don't have more weeds by using corn gluten. Just scatter some before you put down the newspaper, or mix it in with the compost. A WORD OF CAUTION - if you are trying to grow plants from seeds in this spot, DO NOT USE THE CORN GLUTEN!!! it's a pre-emergent, which means it keeps seeds from sprouting. Good against weed seeds, bad for whatever seeds you WANT to sprout.

Either way will work, but the non-roundup way is better for your yard and your immediate environment.

Answer 2

Robert,
This may take a bit more work, however, it will work so well you'll be mailing me back at Christmas.
Go to the tree and step back one stride from the edge of the leaf growth. Place a stake or marker in the turf. Do this at four locations n-s-e-w. Make as, best you can, a true circle using these locations. From the base of the tree to these markers make a cutting of the grass/weeds.
Remove ALL the grass and weeds from the trunk to the markers. The stride you took away from the tree represents the dripline and the area where the tree will uptake both water and nutrients. Round the circle using this drip guideline. Use a shovel and, after removing the grass and weeds, make a trench along that circle for about three to four inches in depth. Push the soil toward the tree.
Depending on the type and height of the tree purchase fertilizer spikes in sufficient amounts. Also purchase either Dyclomec 5-G (generally at a Landscape Store) or Preen with weed control. DO NOT PUT DOWN A LANDSCAPE FABRIC!
The Preen will do fine, however, if you wish to use the spike fertilization, put the spikes in the trench at the recommended level. Do not use either the Dyclomec or Preen until the mulch is installed! These need to treat both the mulch and soil and will not help with the weeds if used before mulching.
Make another small (2") trench about one foot away from the tree. This will be your access in the future and protect the bark of the tree. Mulch with a shredded hardwood mulch at three inches from the front trench to a two inch level at the trunk level. Your front trench will keep the mulch from running off while the back will keep the main roots moist. Apply the Dyclomec or Preen after the mulching operation.
While hard to find (see Landscape Supplier) the Dyclomec 5G will kill weeds already in the soil and prevent them from growth for a season. One and Done. Round-Up is a weekly ordeal. The Preen is Good, however, you may find you need to apply again in early September as it has a shorter life.
Hope this helps. I'm at [e-mail]. Good Luck.

Answer 3

Roundup is the only brand of chemical weed killer I use. I prefer boiling water to get rid of most weeds but sometimes I need something like Roundup to get rid of a whole bunch or just a couple of really tough weeds. Roundup is fairly safe as far as chemicals go. It doesn't leach into the surrounding soil like some other weed killers do. It shouldn't hurt the tree as long as you're careful not to spray it right on the tree but if a bit gets on the tree, it should be o.k. It's best to do this on a day that's not windy. Once you get rid of the weeds you're good to go since Roundup affects only those plants that are sprayed. It leaves no residue in the soil.

Answer 4

Hand weeding is better than putting bleach and vinegar down. Also, if you think Roundup is too expensive, look for an alternative. Roundup is a trade name for a weedkiller made by Monsanto. The active ingredient is glyphosate, which can be found in other brands now, and usually not as expensive as Roundup. Edit. After posting I saw my answer had become redundant! Bearly free is correct and also makes the valid point that feed and weed is for lawns only.

Answer 5

Just in case you might want to consider the long term toxicity to more than the tree. There are long term studies in mice and rats beginning to show reproductive disfunctions. Glyphosate has been found to cause interference in reproductive chemistry specifically interfering in male testosterone production in mice and interfering with an estrogen biosynthesis enzyme in cultures of Human Placental cells
Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase, Environmental Health Perspectives Vol. 113, No.6, 716-720

Williams GM, Kroes R, Munro IC. (2000) Safety evaluation and risk assessment of the herbicide Roundup and its active ingredient, glyphosate, for humans. Regulatory Toxicology and Pharmacology, 31 (2): 117-165.
http://www.naturescountrystore.com/roundup/page9.html

Answer 6

I don't believe it will kill the tree. After all the weeds die off I'd rake the soil or till it just to turn it over and be sure all the weeds were out. Then plant my grass seed. Be sure to water the seed regularly!! Good luck

Answer 7

follow the directions and stick with a scotts owned brand- no it probably won't kill your tree, if you seed asap after the weeds die( post emergents speed up the growth and kill before they can germinate) you should be ok by summer.