Killing Weeds

[JeepMonkey]

How does weed killer work?  I am looking to spray an entire "flower bed" to get rid of weeds to eventually lay down a tarp and rock.  But before I do, I need to get rid of the weeds which have really taken over.

Is it best to leave the weeds full grown, or weed eat down first?  Basiclly, does the week killer absorb through the leaves or the roots?

[Shape D.]

I always just spray the weeds without pulling them. Most of that spray stuff will kill anything it comes in contact with. Weeds, Grass, flowers, Puppies.... I could go on for days maybe It would be easier to list the things it can't kill. John Stamos, and the Grimace.

Seriously though, just spray it; unless you have huge prairie style weeds there that are 3 feet tall.

<edited to add a semi-colon>

[missioncontrol]

spray them because the week killer needs to soak on the leaves, once they die pull them out.

[cdbrown]

make sure it's not going to be raining the day or two after and that any sprinkler system isn't going to water them as washing the poison off the leaves into the ground will do nothing for your cause.

[JackTucky]

I once sprayed a 10 x 10 area of grass and weeds with round up, then immediately put weed fabric and stone over it.

Never had a problem.

Jacktucky

[JeepMonkey]

Good info.

I sprayed my weeds in tact, with a good dose of Round Up.  They were wilting within a day.

Jack,  what was the thickness of the plastic you used?

[cw]

you might want to go with a landscapig fabric... it will let water pass and hold up much longer..

[GregorDV]

I use Ortho GroundClear.  Great stuff.  Takes a couple of weeks before the weeds are dead, but nothing (NOTHING) grows there for about a year.  I use it on all my sidewalks/patios, because I'm _really_ lazy.

[Brax]

How does weed killer work? Basiclly, does the week killer absorb through the leaves or the roots?

Leaves. Most weed killers are kill on contact. The weed has to be alive and growing so it'll spread the poison throughout itself.

If you want to kill everything be sure to avoid the broadleaf only herbicides. If there are any grasses in your flowerbed this won't touch them. You need a complete kill herbicide such as the Ortho brand mentioned above or Roundup. (Although I find Roundup weak and doesn't last. Otho's one year carry-over is nice.)

[ChadTower]

Roundup isn't designed to last.  It is designed to kill what it contacs and then become inert in the soil after about a week.

[clanggedin]

Mix Round-up and 24D. No weed will survive with this deadly combination. They will be dead ina few hours too.

[Dartful Dodger]

The 4th of July is just a few days away.
I'm not suggesting anything.  I'm just saying, the 4th of July is just a few days away.

[DrewKaree]

Sounds like you should have already done this.  Without going into a friggen classroom lecture on this, the herbicides that will work quickly are systemic, meaning you spray them on the plant, the plant absorbs it through the leaves and anything else it touches, and it moves throughout the plant, killing all the way down through the roots. 

What are you putting a tarp and rock down for?

Anyone who tells you (and any landscaper who actively attempts to sell you) landscape fabric should be thrown on a fire ant hill and tied down.

Landscape fabric will ONLY - READ THAT CAREFULLY - O-N-L-Y - ONLY stop weeds from growing if they ALREADY EXIST in the area where you are going to throw the landscape fabric down (which can also be accomplished by throwing several layers of newspaper down and covering them with rocks so it doesn't blow away, plus it will decompose into the ground).  It WILL NOT EVER NEVER EVER NEVER EVER keep new weeds from growing in that area, as the weeds will simply root OVER the landscape fabric.

Add to this the annoyance of someone wanting to run a tiller in that area later to amend the beds and getting the tines caught in the fabric, the fact that you have to cut a friggen hole ANYWAY any time you want to add more plants, and the cost of such a crappy weed "control" product, and you'd be a certified helmet-wearing tool to WANT to throw down landscape fabric.  There's just no dang good reason to use that crap other than misninformation and recommendations from people who make a living at selling/installing that crap.