Return to the Soil Forum | Post a Follow-Up

 o
Does Pre-Mergent Need to Contact the Soil to Work?

Posted by chueh 7B GA (My Page) on
Tue, Feb 12, 13 at 19:33

I am wondering if pre-mergent need to directly contact the soil in order for it to work?

I did spread pre-mergent on some shrub beds, where are covered by landscape fabric and mulch. I did use heavy weight landscape fabric, yet some weeds still creep in. I spread pre-mergent during fall and early spring. However, now I start to wonder if it's worth to do so. The weeds seemed to still merge on anyway... Originally, I was thinking that as long as there is rain soak the pre-mergent and then the water got all the stuff and then run down to the soil. I am starting to suspect that. How silly my thinking is!!!!


Follow-Up Postings:

 o
RE: Does Pre-Mergent Need to Contact the Soil to Work?

I Will be starting to use Pre- emergent this coming spring. I already have purchased it so, your bad luck will not stop me from using it, It needs to be used anyway or it will sit in my barn forever. I hope it helps make the spring new growth more prolific in desired plants, rather than the less desired invasives.


 o
RE: Does Pre-Mergent Need to Contact the Soil to Work?

It actually needs to contact the seeds when they sprout, so it depends on where the seeds are. If you had weedy soil, then put down mulch, then applied the herbicide, it may have less of an effect than if you had put it on the soil where the seeds are.

Also, any chemical applied will begin to degrade and/or leach away as soon as you apply it. So very early spring is better than fall, generally speaking. Unless the directions for your product say differently.


 o
RE: Does Pre-Mergent Need to Contact the Soil to Work?

A pre-emergent weed control product needs to be in contact with the sprouting weed seeds - wherever they are.

If you have weeds sprouting in a mulched bed, it's probably because they blew in or birds pooped them into the mulched area, and they are growing above the landscape fabric. You might do better to just hand-pull the few that sprout instead of using a pre-emergent.

Pre-emergents are best in areas where you have a lot of dirt and a heavy weed crop you want to prevent. After a couple of years, if they are successful, you can switch to post-emergent killing with herbicides or hand pulling.


 o
RE: Does Pre-Mergent Need to Contact the Soil to Work?

Thank you


 o
RE: Does Pre-Mergent Need to Contact the Soil to Work?

Also keep in mind that while many pre emergents are "broad spectrum" a good number of them are selective to either broad leaf weeds or grasses, meaning they will only control one type but not the other. Make sure you're buying a product that is doing what you want it to do depending on your situation.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Soil Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here