+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1
    Join Date
    Mar 2010
    Posts
    12

    Default Organic Crab Grass Killer Suggestions

    Hello,

    I have a 400 sq ft enclosed garden and for the past several years I've had major problems with grab crass.

    Does anyone have suggestions on how to kill crab grass in a organic liquid form?

    Thanks.

  2. #2
    Join Date
    Aug 2007
    Posts
    7,011

    Default Re: Organic Crab Grass Killer Suggestions

    I know of no organic herbicides. Probably your best bet is to cover the area with black plastic to smother it out. This is preferably done when it's fairly warm out so that the grass get's cooked under the black plastic to help kill it. Once you do that, you can scr-ape up the dead stuff and toss it. As new sprouts appear, keep them pulled.

    Now, if you rototill this garden area every year, you're going to be bringing up fresh seed to the surface, which will then germinate. Your best bet is to either NOT cultivate the area, only the spots where your plants are going in, or to cover the area with a thick layer of straw to keep it smothered out.
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

  3. #3
    Join Date
    Mar 2010
    Posts
    12

    Default Re: Organic Crab Grass Killer Suggestions

    Thanks for the reply. I do rototill every year and with your advice I'm going to take the "no dig garden" approach this year.

    The other issue is my walkways... they are layed with stone dust and the crabgrass is a mess.

    I looked up using corn gluten or a vinager and salt mix. Do you have any experience using these products?

  4. #4
    Join Date
    Mar 2009
    Posts
    1,387

    Default Re: Organic Crab Grass Killer Suggestions

    Goats. lol
    Any an all of my comments are just my opinion and not to be confused with facts.

  5. #5
    Join Date
    Aug 2007
    Posts
    7,011

    Default Re: Organic Crab Grass Killer Suggestions

    About the best way to go with your garden plot is to work enough organic materials into the soil so that you do not have to till every year. By not cultivating the ground each year, you can more readily control the unwanted vegetation, as well as save a lot of time and energy tearing up ground that doesn't need to be worked.

    I took a dead garden plot that was nothing but clay and hard pan and in about a year and a half turned it into rich health soil by applying generous amounts of horse manure. Once the ground was worked and amended, it not longer needed to be mechanically worked with a tiller for most items. In fact, it has sat fallow for the past two years and I can go out there and dig with my bare hands. That is the power of organic material and creating good soil.

    The other issue is my walkways... they are layed with stone dust and the crabgrass is a mess.

    I looked up using corn gluten or a vinager and salt mix. Do you have any experience using these products?
    Again, I think I'd first go with trying to smother with heavy black plastic. The darkness will smother the grass, in warmer weather the additional trapped heat will help to kill both the grass and surface seed. I hesitate to recommend using salt or just about anything else because you don't want that washing into your growing areas too. I've not heard of vinegar as an herbicide, acidic as it may be, it is doubtful that it's acidic enough to deal kill vegetation.

    What bothers me most about using herbicide, salt, or caustic substances is that if that material migrates to your growing areas, you're going to have a bigger mess to deal with than just a little crab grass. Be careful and use due diligence in your research before implementing these ideas.
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

  6. #6
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    6,472

    Default Re: Organic Crab Grass Killer Suggestions

    In my war against weed, I've raised my white flag a long long time ago. I can't win this war. Thinking that I could was an expensive idea through the years. Another losing battle is the one with squirrels, for which you'll need a machine gun.

    That's why Spruce has the right approach, for walkways and areas you don't use for growing.

    I have a vegetable garden also and I won't use pesticides, therefore I do a lot of weeding by hand around the plants. Weeding therapy.

    The results are worth the efforts.

  7. #7
    Join Date
    Aug 2007
    Location
    Maryland
    Posts
    1,572

    Default Re: Organic Crab Grass Killer Suggestions

    Corn gluten has some success with crab grass. I think it is organic or at least all natural and is labeled for use with food crops. It is a pre-emergent and needs to be put down before the crab grass seeds germinate.

  8. #8
    Join Date
    Mar 2010
    Posts
    12

    Default Re: Organic Crab Grass Killer Suggestions

    Thanks for all the replies.

    A few more follow up questions:

    What's your thoughts on putting a few inches of straw on top of the base layer?

    Thoughts on using newspaper or card board instead of the plastic as a base layer?

    And for watering, I assume if I go with plastic I will spot water the base of all the plants? I've watered this way since I started my garden.

    Does the plastic base layer need to replaced every growing season?

  9. #9
    Join Date
    Aug 2007
    Posts
    7,011

    Default Re: Organic Crab Grass Killer Suggestions

    You bring up a lot of good points. I usually think of the plastic as a quick, cheap, easy way to cover a large area, but your suggestion of using newspaper and cardboard, is an even better idea because it will break down and become mulch. Since both paper and cardboard are primarily wood pulp, they are the perfect choice for smothering unwanted vegetation.

    Straw is also a good product to use, but be aware that most "straw" is from heavily polluted sources. Both wheat and rice are rife with chemical fertilizers and herbicides, so if you are sensitive or want to stay strictly organic, you may not want to use them. Grass hay and alfalfa make great alternatives, albeit more expensive.

    Installing a drip water system will be the most efficient and least labor intensive means of watering your garden. If you mulch your plants the water provided to each will be retained in the soil and plant rather than lost to evaporation. Mulch will also help to keep the root system cool, which improves the health of the plant in prolonged heat periods.

    When I laid out my garden, I set it up once and use the same layout for several years, thus the same watering system can be reused multiple times. This not only saves you time and money, you are using less plastic pipe and pieces that will end up in the landfill at the end of the year. When I plant the new garden, I lay out the old lines and stake them in place, then I turn on the water to blow out any spiders and debris, then I check to make sure all the emitters are functioning properly, changing out the bad ones.

    If you use plastic or tarps to smother out the non-growing areas, then yes, you'll want to pull those up at the end of each growing season and replace them. If you use paper or cardboard, that can be left year after year and you just add to it as it decomposes. Wood chips/sawdust is another good mulch to use that is beneficial to the ground and not harmful to the environment. Keep in mind that with all wood based products, they will pull nitrogen out of the soil as they decompose, so it's a good idea to test your soil yearly with a home test kit to keep tabs on your nutrient levels.
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

  10. #10
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    6,472

    Default Re: Organic Crab Grass Killer Suggestions

    Just a note regarding the use of newspapers and cardboards: they contain ink, glue and other chemicals I wouldn't want in my vegetable garden. For similar reasons I won't use treated lumber in a produce garden.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •