Organic Herbicides and Pesticides

The dandelion bloom

David Beaulieu

Do you seek green yard care products? Certainly, organic herbicides and pesticides will be near the top of your list. Consumers seeking eco-friendly yards will find the information below helpful to consult before choosing products.

  • 01 of 06


    Strange that something you put on a salad should act as an herbicide, right? But here is the key thing to remember: Vinegar contains acetic acid. Even more important to remember is that types of vinegar with higher percentages of acetic acid will be more successful as organic herbicides. Unfortunately, the vinegar in your cupboard has a low percentage of acetic acid. It will still kill weeds, sure. But you may have to apply it a number of times. A lot depends on the tenacity of the particular weeds; dandelion is a relatively tenacious weed.

    If the idea of using vinegar as an organic herbicide really interests you, you can check at farmer's supply stores for kinds of vinegar that contain higher percentages of acetic acid. 

    This article elaborates on vinegar's limitations as a weed killer, how to use it, and when to use it. And incidentally, while we are discussing things found in the kitchen that can function as organic herbicides, note that even boiling water can work pretty well on some weeds.

  • 02 of 06

    Nature's Avenger, Garden Safe Herbicides

    "Garden Safe" and "Nature's Avenger" are examples of organic herbicides. Garden Safe uses natural botanical pyrethrins, while Nature's Avenger is based on natural citrus oil.

    But the problem with such commercial organic herbicides is the same as one encounters when using vinegar as an organic herbicide (see above): While these sprays kill annual weeds just fine, the tougher perennial weeds tend to hold their ground.

  • 03 of 06

    Neem Oil Insecticide

    This reviewer had a good experience recently using organic pesticides. This spring, he became aware of an aphid invasion on his ninebark shrub. He used an organic pesticide named "70 percent Neem Oil" on the leaves. After spraying every seven days for three weeks, he is glad to report that he found no more aphids on the bush.

    He has also had success killing aphids with Neem oil on the following plants:

    Neem oil is also supposed to be effective against a number of other garden bugs, including Japanese beetles, for example.

  • 04 of 06

    Safer Soap Insecticide

    "Safer" is a brand name, with an obvious allusion to it being less harmful to the environment and to humans than the typical insecticide. Safer Soap is an organic pesticide that kills spider mites, thrips, earwigs, and more. It works by breaking down an insect's cell membranes. Now lacking the protection afforded by these membranes, the insect's cells are compromised and lose their contents; the result is that the insect suffers dehydration.

    Continue to 5 of 6 below.
  • 05 of 06

    Hot Water

    Hot water is the ultimate organic herbicide in terms of being cheap and readily available. Like vinegar, it will not kill the toughest of weeds. But if you have just boiled a vegetable for dinner on the kitchen stove and need to dispose of the hot water, why not pour it on those crabgrass weeds coming up through the crack where your driveway meets your patio? As an annual weed, crabgrass is not quite as tough as dandelion and will succumb to scalding hot water.

    As with other organic herbicides, the fact that hot water is "green" does not mean that you can be careless in using it: It will damage your "good" plants if you mistakenly get some on their leaves. But if you stay faithful regarding that one warning (and if you remember its limitations), you may come to regard hot water as the best thing since sliced bread in the world of weed control without chemicals.

  • 06 of 06

    Warnings About Two Additional Organic Heribicides

    To round out this list, let's consider two other methods for killing weeds sometimes recommended:

    • Using a salt solution.
    • Using fire.

    A solution of salt (one part salt to three or more parts water) will, indeed, kill weeds. However, it is recommended that you spray this solution only directly on the foliage of the weeds you're battling--without getting much of it on the ground (or on other plants)--since excessive salt content is bad for your soil. But a spray is, by its very nature, difficult to control, which should make one leery of relying too heavily on this method.

    As for using fire to kill weeds, you can now buy flame-weeder tools. For example, the Northern Tool and Equipment company sells a Weed Dragon Torch Kit (100,000 BTU), which is also available on Amazon. The advantage of such tools is that you can use them for other purposes, as well, such as:

    • Firing up the backyard grill.
    • Melting ice in winter.

    The primary disadvantage is the one under which you always operate when using fire: the risk of accidentally setting something on fire that you do not want to be burned.

    Therefore, while these products can be effective, the sensible conclusion to draw is that there are simply better alternatives out there, considering:

    • How dangerous fire is to handle.
    • How easily the use of salt can have unintended consequences.