Organic Weed Control

How to Kill Weeds Without Harmful Chemicals

Photograph of a Lawn Being Seeded - Organic Weed Control

It's that time of the year when our lawns are still dormant, but cool seasonal weeds are beginning to pop up in the lawn and landscape. The 14th century reformer, Martin Luther, once said, "You can't stop a bird from flying over (or landing on) your head, but you can stop it from building a nest in your hair." While no lawn or garden will ever be 100% weed free, we can keep the weeds from taking over your lawn. Organic weed control involves a multitude of gardening techniques and it is quite possible to have a weed free lawn & garden and not use toxic synthetic chemicals.

Organic weed control is much more than killing weeds safely. It is first about growing healthy turf in fertile soil and minimizing weed pressure. Organic weed control is further achieved by using an Integrated Pest Management (IPM) program to establish weed thresholds, prevent weeds, and eradicate as a last resort.

There is no quick fix, magic spray weed killer in organic lawn care. Organic weed control is more about the holistic organic management of the lawn and soil, which results in fewer weeds. The theory (and practice) being that a healthy lawn and soil will promote turf growth which will out-compete weeds.

The first thing to understand is that the health of the soil is the key point in creating a weed free lawn. Healthy soil yields a healthy lawn and landscaping that will resist weeds. Use organic fertilizers, compost and organic soil amendments to build the health of your soil. Sow grass seed in the spring to thicken up your lawn. Trim and thin out the canopy of your trees so that your lawn receives the proper amount of sunlight. (Remember, Bermuda grass needs a minimum of 8 to 10 hours of direct sunlight every day to be thick and healthy. St. Augustine needs a minimum of 4 hours of direct sunlight.) Also, over watering or areas in your lawn where the water drains poorly and the soil stays moist will also cause your lawn to be thin and sickly. Our southern grasses must completely dry out between waterings in order for them to be green, lush and weed resistant.

Correct cultivation practices must be performed to reduce the opportunity for weeds to thrive. Weeds thrive on weak, stressed out turf and compacted, unhealthy soil. Eliminate those conditions and grass will win over weeds.

Photograph of a Lawn Being Scalped
While "scalping" your lawn is a fairly common practice, it will actually weaken your lawn's root system and make your turf susceptible to a variety of weeds and diseases.
  • Mow at the highest level possible to encourage a dense lush, lawn capable crowding out of weeds.
  • Reduce soil compaction by aerating your lawn.
  • Improve water and nutrient uptake by de-thatching with our microbial compost tea.
  • Topdress with Spriggs Brothers organicly enriched compost and soil amendments.
  • Re-seed bare spots or thin lawns this spring to avoid them from being taken over by weeds.
  • Avoid scalping the lawn when mowing. Damaged crowns recover very slowly and give weeds an opportunity to establish.
  • Water deeply and infrequently, maintain adequate soil moisture but do not over-water.
  • Apply corn gluten meal, an organic pre-emergent, @ 20 lbs per 1,000 sq ft in your lawn in mid February and a second application 4 to 6 weeks later (March/April). An average size lawn will need 80 to 120 lbs of organic pre-emergent per application. Corn Gluten Meal suppresses seed germination and provides a quick green up for your lawn.
  1. Weeding by Hand

    Photograph of a Lawn Being Weeded by Hand
    Use a gardening tool to remove weeds from your lawn and landscape, or remove them by hand.
    Some people are choosing a more dramatic organic gardening measure to control their weed populations. In the West, hiring a herd of goats to eat weeds is quickly gaining popularity. Goats prefer to eat brush, leaves and twigs. They munch grass only as a last resort.

    Now, I don't think we need to resort to goats. But hiring your kids (or hiring Spriggs Brothers) to spend a few hours hand weeding will keep the weeds from taking over your lawn and landscaping. The best way to manually pull weeds is to grab the plant close to the ground, encircling its leaves with the fingers of one hand, using a small-bladed knife or sharp-edged weeding tool. Use it in the soil to slide under the roots of the weed to loosen them and help remove the plant from the soil. Be sure you get the roots of the weed. Throw the weeds into a compost pile or the trash. Do not leave the pulled weeds on the ground. Many weeds have seeds that will germinate and multiply your weed problem.

  2. Spot spray the weeds with an organic post-emergent

    Now, while the grass is dormant and the weeds are green, is the best time to spot spray the lawn with an organic herbicide. Acetic acid in vinegar has plant killing properties and can be used as a non-selective weed killer. Household vinegar does not get above 5% acetic acid and weeds would need repeated applications.

    We recommend using a 10% vinegar based herbicide with orange oil, molasses and bio wash. Spraying a vinegar herbicide on dormant grass won't harm your turf, but if you over seeded with winter rye or fescue, the vinegar will kill the cool season grass. You can buy the organic postemergent at the organic store. If you don't know where to buy the post-emergent, we will sell you a gallon of our recipe, or you can hire us to spray your lawn for weeds.

  3. Let nature burn out your weeds in your lawn

    Photograph of Henbit
    Photograph of Annual Poe
    Annual Poe (Bluegrass)
    Many of your cool season weeds, but not all weeds, will die out when the temperatures get to be in the mid to upper 80 degree mark. Henbit, annual poe (bluegrass), and other cool season weeds will naturally die off in the warmer temperatures, especially if they get direct sunlight. When the temperature warms up, usually April/May, mow and bag your lawn to 3/4 an inch shorter than normal for two weeks in a row. Put down a high nitrogen organic fertilizer or corn gluten meal, and your weeds will naturally die and disappear.

    We recommend that you diligently follow the first two steps in steps in February and March and then when the temperature warms up, nature will finish off the job. Using multiple methods is the key to successful weed control. Combining different strategies brings excellent results.

  4. Control the weeds in your flowerbeds

    Photograph of Soil in hand
    A good 2 to 3 inch layer of shredded mulch is a great way to prevent weeds from taking root in your landscaping and gardens. Avoid pine bark or other mulch "chips", as these will wash away after a heavy rain.
    After hand weeding the flowerbeds, put down a 1/8 inch layer of newspapers as an organic weed barrier. Wet it down so it won't blow away. Then add a 2 to 3 inch layer of hardwood or cedar mulch. The newspaper will compost into the soil and along with the mulch will help build healthy soil. The newspapers will be an effective weed block for 6 months, or about the same time you need to replenish your mulch in the fall.

    We recommend that you add lava sand, green sand, corn meal and molasses to your flowerbeds before you put down your fresh layer of mulch this spring. Work the soil amendments into the soil, loosen the soil up to alleviate soil compaction and to get oxygen and nutrients around the root zone or your shrubs and perennials.

Leave a Reply

Your email address will not be published. Required fields are marked *