weed killer basics

[Mosey]

When I had some estimates done for paving my driveway, they said they would spray the area with Roundup first, then wait a week or so to let it kill everything before doing the grading and prep work. Then, after that they said they would spray with another type of weed and grass killer (petronal or something like that, I don't know how to spell it) before paving in order to "kill the ground" to make sure no new stuff tried to come up through the pavement.

My question is, will any of this stuff hurt trees if they spray it over the roots? I have 3 nice maples about 6 feet from the edge of the driveway and I'm sure the roots go under the drive all the way across it. From what they described, it sounds like they'll be spraying the entire area so they will be spraying a lot of this stuff. I don't want anything to happen to the trees!

Also, I've been using Spectracide and Roundup brands of weed and grass killer to keep the weeds down in the center of the driveway. The Spectracide seems to work much faster, but the Roundup seems to last longer. Is that what others have experienced?

 

[Turfman]

The closest thing I could find to the name you mentioned is patron 175. It can be harmful to trees, through the roots. It is not generally used as a bare ground herbicide, but can be.

One of the standard bare ground herbicides is PROMETONE, also known as pramitol. I have seen many trees killed by applications of this and other similar products. It gets placed down on the ground and water moves it to the trees. It is sometimes used under asphalt for road construction. Trees in the parking strip begin to die in a few years. There is no way to reverse the effect or to prevent it from happening.

Most tree roots spread out about 3 times the height of the tree. A 10 foot tree has a root span that is 30 feet in radius or 60 feet in diameter. 75% of the roots are in the top 18 inches of the soil, so they are close to the application of the herbicide. The hair like feeder roots are at the tips of the root growth and are most suseptable to the up take of the herbicide.

You need to decide the worth of the application to you, but I feel like you risk your trees by applying the herbicide.

If I had a better name on the product I could give better advice. Best of luck in you decision.

Turfman

 

[gerard]

triox is a name brand of a "soil sterilant". put down on bare earth the soil will not grow anything for one year from appliacation. Used a lot for gravel parking lots etc.

 

[beenthere]

Interesting problem. Maybe the drive installers need to kill the roots of the maples under the drive, so they do not push up the asphalt. But, feeding your trees with this stuff through the roots under the drive may kill them. I would consider trenching along the drive to sever the roots of the maple trees, thus protecting them from taking up the chemical. New roots will probably not have the chance to get established under the new drive, and therefor not draw in the residual chemical. Just a thought, as you don't want the new drive buckled by maple roots underneath (and maples are bad for roots at the surface) and you don't want to lose the maples.

 

[Mosey]

"PROMETONE, also known as pramitol" … "triox"

Sorry, my bad memory is failing me again, that might have been it, but I just don’t remember the term he used. I’ll call him and find out. Thanks.

 

[mrcaptainbob]

I've heard of copper wire being wound around drain pipes to keep roots from seeking the water. I've also heard that a 3/4" copper spike nailed into a tree will kill it. Too bad we can't get copper sheet a foot or so wide and however long to use it as a barrier alongside the drive, much as the plastic grass barriers are used around the flower beds.That would keep any roots from snaking under the drive. But the cost!!!/w3tcompact/icons/shocked.gif

 

[Mosey]

I got the name of the stuff - sort of. He they were using "per-ma-tol" or "per-met-all" or something like that (I still don't know the spelling) for a long time. He said they aren't allowed to use it any more and are using something else, but he couldn't remember the name. He said it could harm trees if they aren't careful. I think I'd rather take my chances on the pavement cracking rather than take a chance on harming the trees.

 

[Turfman]

That would be the pramitol I refered to in my previous post.

 

[Mosey]

Turfman - I finally got the spelling and pramitol is what they said. One guy said they (not sure who "they" are) don't allow it anymore, so he uses some other product he couldn't remember the name of. Another guy said he uses pramitol, but claimed it won't damage trees. He said even using pramitol with only one application some weeds will still come up through the asphalt. I'm amazed that weeds would come up through 3" or more of asphalt! All this is taking away all of the fun and excitement of getting the driveway paved.

 

[MikePA]

Danny,

Here's a <A target="_blank" HREF=http://www.pramitol.com>link</A> to the Pramitol web site. Looks like it's still available. There are 5 distributors in IN.