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As a matter of principal we don't spray Glyphosate (Roundup) or other herbicides on our property. I'm well aware of its effectiveness as a non-selective herbicide but choose not to use it for a number of reasons.

I've got a few hundred feet of paved driveway which has some areas where weeds (mostly Bermuda grass) is pushing up through the asphalt. Weeds are pretty hard on the driveway edges, breaking it up if left unchecked.

I have a flame weeder which is quite effective at killing off vegetation by heating them up and breaking down the cell structures of the leaves and stems. But this doesn't work all that well on the driveway and not all that well on Bermuda grass - at least not in my experience.

I've used vinegar before and it is OK at killing weed top growth but not so great for plants with considerable roots or those that spread using rhizomes.

Generally I just pull out the mattock and get medieval on weeds - the mattock is a very effective tool for digging out weeds - but along the driveway this isn't really an option.

Ideas?

  • I've got a similar situation, but along a chicken-wire fence that surrounds my garden. Interested to see a good response that is not susceptible to run-off. – Doresoom Jun 6 '13 at 14:19
  • I've found the flame weeder effective along chicken wire fence for weeds that are mostly top growth. – itsmatt Jun 6 '13 at 14:22
  • The fence has cedar 2"x2" posts. I've never used a flame weeder before - would the post material pose a problem, or is it a short enough duration sweep that solid wood would not be effective? – Doresoom Jun 6 '13 at 14:26
  • So you don't so much burn the weeds as heat them up. A quick pass over them makes them shrivel a bit. At that point, the damage is done to the weed. Mine is on a dolly-like cart that I wheel around. I carry a spray bottle of water on the cart for any little flames that pop up (sometimes they do) and I generally flame weed only when the ground isn't really dry. I've found it quite effective even right after a rain when everything is wet. All that has to happen is have the plants heat up so they are damaged. Wet ground will keep fires from starting. – itsmatt Jun 6 '13 at 15:02
  • Are the weeds along the edges of the driveway or in the interior? – BRM Jun 6 '13 at 17:58
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I'm not very familiar with bermuda but all the organic weed and grass killers I've come across basically work by desicating the plant. None seem to kill the plant down to the root. Eventually though it's claimed that the plant will use up it's energy reserves in the root and it won't come back. Have you tried applications of vinegar or flame weeding on a regular basis?

I only spray my driveway and walks once or twice a season but I understand that bermuda is very aggressive and you might need to spray more often.

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If you don't want weeds - ever - to grow somewhere, then it seems to me you should change the nutrient levels in the dirt to make it so nothing can grow. Otherwise you're just going to have to keep killing things forever.

Healthy soil nutrients are Ca++, Mg++, K+ mainly and without these, no plant is going to grow. So if you apply bleach (NaClO) and/or table salt (NaCl), you will bath the soil in Cl- and Na+. The Cl- will bind with a lot of the Ca++, Mg++, and K+ while the Na+ takes their places. You'll have soil composed mainly of Na+ (sodic soil) and nothing will grow. No harmful chemicals have been applied and to reverse the process, you simply add lime (CaCO3), epsom salts (MgSO4), and potassium chloride (KCl) from any ole cheap fertilzer at walmart.

The flame-thrower idea is more fun, but using it on galvanized steel (ie chicken wire) could burn off the zinc and allow the steel to rust.

  • 1
    but if you apply chlorine or salt these will ultimately leach into the water table and will have to be reapplied (depending on yearly rainfall levels). – kevinsky Jul 2 '13 at 22:14
  • Yes the Cl will leach away, but the Na will remain adsorbed to the clay particles where the Ca, Mg, and K used to be. The trick is to produce a sodic soil. The Cl is really inconsequential. The Ca, Mg, and K won't come back unless there is some source of it. – Randy Jul 3 '13 at 1:43
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    I like this idea because it is beyond going medieval on the weeds and is going Roman on em! en.wikipedia.org/wiki/Salting_the_earth – dkackman Aug 1 '13 at 18:17
  • @dkackman Wow! Never knew that. Kinda like pouring salt in the wounds. +1 – Randy Aug 2 '13 at 5:58
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What acidity was the vinegar that you used? They now sell horticultural strength vinger that is up to 20% acidity which will do a much more potent job than white vinegar from the cupboard which is 5% acidity.

I've yet to come up with any surefire solution. Even before I went 100% organic, I could not keep weeds out of the cracks using Round Up or other "kill everything" sprays. Now I employ the following practices:

  1. Spot treat with a vinegar spray for big broadleaf weeds.
  2. Manually clean the cracks every so often
  3. Spread corn gluten meal in the spring and fall. Corn gluten meal inhibits root formation after a seed sprouts. It is not 100% but I have a noticeable decrease in weeds since I've started using it. It takes a year or two to really have a cumulative effect.

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