Herbicide (weed/grass killer) Basic Information

[thatguy]

I thought Id share this page I found online - its sorta a newbie/intro to weed/grass killers that I found useful.. I get overwhelmed at the amount of choices you have when buying herbicides, and I realized a lot of times I buy multiples of the same chemicals from different mfg's because I didnt look at the ingredients.

In a nutshell it seems that the three listed below are sorta all you need and appear to be most commonly available around here. Your need may require a combination of these though.

Glyphosate - will kill both grass and weeds, but may need some help to kill shrubs/bushes/woody plants (see Triclopyr below)

2,4d - will kill your broadleaf weeds (not your grass) but will not work well on shrubs/bushes/woody plants

Triclopyr - works best on killing bushes/shrubs/woody plants. It will also kill broadleaf weeds (safe for grass though)..



This information came from here: Weed killers review - Weed Identification & Control - PlantCare.com But i will cut and paste for easier reading..

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Weed killers review

Choosing the right one to treat your lawn or garden

Weed killers are available in all varieties. As a gardener or homeowner, you may wonder how to choose the right one to care for weeds in your vegetable garden or front lawn. The truth is, weed killers can do more damage than good if they're not used correctly, so it's important to do some research.

The following weed killers have been chosen because they're ideal for home use. Read the information carefully, and if you decide to purchase a weed killer make sure to follow all directions to the letter. Taking a few precautions will help protect you as well as your plants and environment.

Common weed killers

Glyphosate
This non-selective weed killer is available in concentrated or ready-to-use forms. It is usually sold under the brand names Roundup and Kleenup and is often referred to as "weed and grass killer." Because it is non-selective, it will kill anything in its path and should not be used on lawns. If you're spraying weeds in the garden, do so on a calm day or use a piece of cardboard to shield other plants from spray-over. Glyphosate kills weeds to the root, versus some weed killers that simply kill the visible part of the plant.

Products containing glyphosate neutralize upon contact with the ground, making them safe for soil.

Diquat
The chemical called diquat is usually sold under the brand name Weedol (in the UK) and Reglone in the United States. Diquat works more quickly than glyphosate and is designed for killing small weeds that grow inside of shrubs, because it does not harm woody stems. It will kill grass and is known to pollute drinking water, so check local regulations before use.

Diquat is most commonly used on potatoes and cotton. It does not attack the roots of a plant and so is not helpful against perennial weeds.

Triclopyr
Brush-B-Gon and other types of brush killer are common examples of the chemical triclopyr. This weed killer is designed for use on woody or broadleaf plants, such as unwanted shrubs or bushes. It does not harm grass but can do damage to other, desirable bushes, so application should be done with care. This weed killer should be applied to foliage or cut stems so that it can work its way down to the roots.

Trimec (2,4-D)
Trimec is a hormone identical to that created by leaves as they grow. When applied to the leaves of a weed, trimec confuses the plant to death. This chemical targets broadleaf weeds such as crab grass and does not harm regular grass. It should be used with care to make sure it doesn't float onto surrounding trees or shrubbery that you don't want to kill. Most products containing this chemical have a name that contains it, such as Gordon's Trimec Weed and Feed.

Choosing a chemical weed killer can be difficult, but your best defense against residual damage to your plants is reading the label. Check out the instructions on the weed killer thoroughly, and read the active ingredients to see what kind of chemical you're buying.

Regardless of what type of weed killer you're using, the safety precautions will remain mostly the same. Wear long sleeves and gloves when handling weed killer, and a protective mask if the chemical is in a liquid form that may create spray-back. Keep children and pets away from the area until the weed killer is completely dry. Store all chemicals in a safe area on a high shelf, and make sure lids are tightly closed.

 

[clemsonfor]

This is the simple version, none of the restricted are mentioned, that adds a whole new level to confusion, to even those like me in the idustry that uses them. I havee a general idea but dont use it allday everyday so i am some what lost on the restricteds. But they are just that restriced so you need a license to buy and apply them.

There are some restricteds that make roundup look like liquid fertilizer. Allthough roundup (41% glyphosate is used in tank mixes for righofway spraying by most it is not the most powerful. Garlon and some others get that some soil herbicides you wont grow hardwood there for 2 years or so. Others like Arsonal can be sprayed over pine and not harm the pine but smoke eerything else from grass to hardwood.

Sorry to confuse but that is not an inclusive list of all of them.

 

[MMagis]

This is the simple version, none of the restricted are mentioned
Sorry to confuse but that is not an inclusive list of all of them.

No one said it was. In fact, his first paragraph says these are just the three most common and all most people will need to use.
Very good info for people not familiar with herbicides.

 

[clemsonfor]

Agreed on the info is good. Sorry i missed that i was scanning that as i already and familiar with those, sorry, i speed read it which mine is not that great.

 

[johnk]

What is a good killer for Japenese Knotwood. That is some nasty stuff and i have a few plants invading my small garden? Thanks...

 

[clemsonfor]

Japaneese Knotwood?? Is that a common name or local name. I have not heard of it. Glyphosate kills most everything (41%) id start with that, it may take 2 applications though. If not that i would try and get ahold of some restricted stuff, like garlon, it kill it dead as a hammer.

 

[johnk]

I am sorry it is Japenese knotWEED. Some really nasty stuff that is VERY hard to eliminate.
Yahoo! Image Detail for - http://y2u.co.uk/Knowledge_Information/japanese_knotweed_fallopia_japonica.jpg

 

[Pilot]

"Trimec is a hormone identical to that created by leaves as they grow."

I am not so sure this is technically accurate. 2,4-d is a plant hormone, but an artificial one similar to naturally occurring indole acetic acid which is probably one of the most important plant growth regulators. IAA tells roots to grow downward, stems to grow upward, leaves to drop in the fall and regulates several other functions. 2,4-d is almost the same chemical structure except one part of the molecule is different. As such the plant sees it as indole acetic acid, but it doesn't perform the same and upsets, distorts and destroys physiological functions.

 

[forester2]

Trimec is not 2,4D. It contains 2,4D as one of the 3 chemicals in it's make up. It also does NOT control crabgrass which is NOT a broadleafed weed.

 

[johnk]

Trimec is not 2,4D. It contains 2,4D as one of the 3 chemicals in it's make up. It also does NOT control crabgrass which is NOT a broadleafed weed.

What about my my Japenese Knotweed. This is some nasty stuff!

 

[rswyan]

Trimec is not 2,4D. It contains 2,4D as one of the 3 chemicals in it's make up. It also does NOT control crabgrass which is NOT a broadleafed weed.

But Trimec Plus supposedly does ..... (never used it myself)

 

[James150]

Japanese Knotweed . . . .Nasty stuff. Cut the stems and inject or paint them with roundup while they are fresh.

This stuff travels underground by runners up to 40'. I've seen it come up through asphalt or packed down gravel.

We had a stand 40' X 60' and ten feet high when we bought our land ten years ago. I cut it, I burned it, I poisoned it and except for a few shoots I'm always cutting with the mower that come from the cornfield next door, I'm knotweed free.

I have no illusions that if I stopped cutting and poisoning it would be back in full force in a year or two.

BTW, it also propogates from small pieces, so if you cut it, and part of a plant is washed down into the ditch, it will take hold and wreak havoc. Nasty stuff.

Jim (BTW, I'm in ag zone 4 in SW WI)

 

[johnk]

I am going to try the Roundup route after the garden quits producing in a week or so. I was planning on cutting the whole garden down, spraying, waiting a few days, rototilling and spraying again. Ur should I not rototill and selectively spray the Knotweed?

 

[clemsonfor]

Spraying the whole garden depends on weather you want to spend the money to do that size area, it will not hurt as you will kill all the weeds and grasses. I would also spray it weather you spot spray or do the whole area and let it sit at least a week if not 1.5 weeks to make sure that the chemical gets into the roots from the leaves. (If your not aware this is how it works the leaves take it to the roots through transpiration or whatever you call it where it takes the carbohydrates made in photosynthesis to the roots)

I would buy generic roundup at landscape suypply places it is much cheaper than roundup (unless your using roundup as a name for the chemical glyphosate). Make sure you get 41% glyphosate. You can buy it at landscape places for less than $50 for 2.5 gallons of concentrate and you mix 4 oz/gallon. I got the last gallon from a guy i have contract work done for a place i manage, he buy it 100+ gallons at the time so he gets a deal. I got him to get me some i paid him his price $15/gallon.

 

[johnk]

Thanks for that info Clem. Do you suggest tilling after a week and respraying to make sure I got all the seeds and runners??"?

 

[Pilot]

Roundup (glyphosate) is taken up thru the leaves--it will not affect the seeds. After it is taken up thru the leaves it is translocated internally to the roots, which it then kills.

Spraying after tilling won't do a thing unless there are some leaves exposed on plants that somehow would otherwise survive.

Spray it once, spray it thoroughly and you're good to go.

Roundup no longer moves thru the plant after 72 hours, so waiting longer to till than that gives no benefit.

Be sure to use a sticking (wetting) agent, one that is made for herbicides. Don't bother trying to use detergent, it won't work nearly as well as the stuff made for the purpose. The glyphosate I buy has the sticker in it; it costs about $5 more per 2.5 gallons than the stuff that doesn't have it.

 

[clemsonfor]

John and piolot , your both correct.

John if you spray after tilling and you hit a live root it will kill it by hitting it with roundup, not as well as leaves but that is a surface that can uptake something to the plant, it is a root afterall.

Roundup is not soil active and turns to harmless crystals once in soil so technically you can plant in the soil once sprayed, the danger comes in as your tender new growth may contact an leaf that still has residue on it that in the mourning dew rehydrates the herbicide thus transferring it to the new plant. This is the reason you see the warning on the bottle , like wiat 10 days to plant veggies etc.

Id wait in my opininon at least 5 days till it then wait 2 weeks for resprouts and new seeds to sprout and spray it again, that should get most of the stuff.

Piolot, you dont just have to hit leaves, green stems like on grasses and flowers can cause death, also you can girdle or cut a sapling and spray the stump when wet and fresh and that will translocate the poison to the roots for death. Leaves are optimum but not a hard fast rule. Woody stems not a problem, like my crepe myrdle i just spray around the base i dont care if i hit the trunk, it dosent do anything as it cant go through the bark/woody stem. Or if your spraying around your big oak tree so you dont have to weed eat just spray grass around it 10"s or so and dont worry about over spray onto the tree it is harmless to it, on the trunk that is.