Posted on

how to destroy weed seeds

6 Fast and Natural Ways to Kill Weeds

It’s summer time and the weeds are growing like, um, weeds. Instead of reaching for a toxic chemical that could be harmful to your family or pets, try one of these easy natural ways to kill weeds quick.

  1. Use mulch to smother weeds. Covering garden soil with a mulch blocks weeds. Use two or three inches of shredded bark, wood chips, straw, cocoa bean hulls, gravel or rocks. The mulches will also keep moisture in the soil so you’ll have to water less frequently.
  2. Douse weeds with boiling water. Weeds, like humans, will burn if exposed to boiling water. This method also kills weed seeds.
  3. Soap weeds to death. Mix 5 tablespoons of liquid soap (such as dishwashing liquid) in one quart (4 cups) of water in a spray bottle. Coat the weeds with the soapy water. Works best on hot days.
  4. Pickle weeds with vinegar. Pour household vinegar into a spray bottle and evenly coat weeds with it. U.S. Department of Agriculture scientists recently confirmed this in tests. Vinegar is really five percent acetic acid in water, and it burns the plant, especially on sunny days. For extra strength weed killer, look for pickling vinegar, which is nine percent acetic acid. Don’t get the vinegar on your garden plants, as it can kill them too.
  5. Give weeds a stiff drink of alcohol. Mix one to five tablespoons of alcohol – depending on how stubborn the weeds are – with one quart (4 cups) of water in a spray bottle. Shower weeds with the spray. Don’t let the alcohol get on garden plants as it may damage their leaves.
  6. Don’t let ‘em sprout! Use corn meal gluten as a pre-emergent herbicide and fertilizer. Corn meal gluten prevents weeds from growing, then breaks down to provide nitrogen to your plants or lawn. Use it on lawns or established perennial beds, as it won’t kill already growing plants. That does mean, of course, that it won’t work on already existing weeds.

Latest Blog Posts on WebMD

How Migraine Impacts My Social Life

If you know someone with migraine, you may think they struggle with really bad headaches. Well, it’s true .

Tipping the Scales in Your Favor

Let’s talk about the subject that no one wants to talk about, that evil four-letter word: DIET. I’m sure you have heard that changing your diet will affect how you feel. I wasn’t a believer .

Important: The opinions expressed in WebMD Blogs are solely those of the User, who may or may not have medical or scientific training. These opinions do not represent the opinions of WebMD. Blogs are not reviewed by a WebMD physician or any member of the WebMD editorial staff for accuracy, balance, objectivity, or any other reason except for compliance with our Terms and Conditions. Some of these opinions may contain information about treatments or uses of drug products that have not been approved by the U.S. Food and Drug Administration. WebMD does not endorse any specific product, service or treatment.

Do not consider WebMD Blogs as medical advice. Never delay or disregard seeking professional medical advice from your doctor or other qualified healthcare provider because of something you have read on WebMD. You should always speak with your doctor before you start, stop, or change any prescribed part of your care plan or treatment. WebMD understands that reading individual, real-life experiences can be a helpful resource, but it is never a substitute for professional medical advice, diagnosis, or treatment from a qualified health care provider. If you think you may have a medical emergency, call your doctor or dial 911 immediately.

Lecture 3: Fumigation

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.

English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Estoy de Acuerdo / I agree


  • Fumigants kill weed seeds and vegetative propagules
  • Fumigants are TOXIC
  • For all fumigants: site preparation is critical to product performance

Fumigants available

  • Metham Sodium (liquid)
  • Basamid (granules)
  • Steam

For Best Results Soil Should Be:

  • Cultivated to 8 inches
  • Free of plant debris and clods
  • 55 F at 6 inches
  • Moist, Not wet
  • Amended before fumigation

Methyl bromide

  • The quickest, most versatile & effective
  • No longer available

Metham sodium (formerly Vapam)

  • Liquid application
  • Tarp helps but can be “sealed” with irrigation
  • Time: 7 days, then shallow cultivate, then wait another 7 to 14 days

Basamid (dazomet)

  • Granular application
  • Rototill, then seal surface & irrigate
  • Time: 7 days, then shallow cultivate, then wait another 7 to 14 days

For best results with Metham or Basamid

  • Use a tarp
  • If not, keep soil surface moist for 7 days. (This seals the surface and traps the vapors)

Steam Pasteurization

The soil should be maintained at 180oF for a minimum of 30 minutes. This treatment is sufficient to kill most pathogenic organisms; however, many weed seeds will escape .


Similar to pasteurization but using solar energy to heat the soil in order to kill pathogens, arthropods and weeds. Cover the soil with CLEAR plastic during the summer. Preferably elevate the plastic to trap more heat. This works well in regions that have high solar irradiance but not as well in NC. Small-seeded weeds (such as chickweed and henbit) can be suppressed but perennial weeds (like bermudagrass and nutsedge) and large-seeded weeds (like morningglory and smartweed) are generally not well controlled.

Common reasons fumigants don’t work

  • Soil too wet or too dry
  • Soil too cold
  • Heavy soils not cultivated to adequate depth
  • Some hard-seeded weeds are not controlled (clover, Car. geranium)


Prevent the introduction of weed propagules
Top soil, organic amendments, weeds in adjacent property, balled and burlapped plants

Study Questions:

  1. Compare and contrast how the mode of action of fumigants differs from that of preemergence herbicides.
  2. List the 3 main chemical fumigants. Compare and contrast them with regards to how rapidly they work, covered / not covered/ toxicity / formulation / how they are applied
  3. Compare and contrast steam pasteurization and solarization.
  4. Describe the site preparation necessary to achieve maximum benefit from a soil fumigation.
  5. What are the common reasons why soil fumigation may not work.
  6. What types of weeds would likely be controlled by soil solarization in NC?
  7. What types of weeds would likely NOT be controlled by soil solarization in NC?
  8. List 2 weeds that would likely not be controlled by Methyl Bromide fumigation.
  9. When will Methyl Bromide no longer be available?

More from Landscape Weed Management (CS 053)

Written By

Brandon Hopper Business and Technology Application Technician Call Brandon

Dealing with weed seeds, pests on spruce trees

A. To kill weed seeds during the composting process, the pile should reach 140 degrees F for at least two weeks. Some of the more resistant species may not be killed even by this treatment. For a small compost pile, achieving a high sustained temperature may require insulating the pile (e.g., with loose straw over plastic). If the weather is warm and sunny, the heat generated by biological activity can be supplemented with solar energy by covering the pile with clear plastic. Since the outside of the pile is unlikely to attain the required temperature for a sustained period in any case, thoroughly mixing the pile several times will probably be necessary. For a very small pile (less than 1 cubic yard), attaining a high enough temperature for a long enough time to kill most weed seeds may be impossible.

To construct a hot compost pile, home gardeners will need a combination of bulking agents and energy materials. Bulking agents, sometimes called “brown materials,” are dry, porous materials that help aerate the compost pile. They can be such things as wood chips, sawdust, grass hay, wheat straw and corn stalks. They are too low in moisture and nutrients to decay quickly on their own. Energy materials, sometimes called “green materials,” provide the nitrogen and high-energy carbon compounds needed for fast microbial growth. They include grass clippings, fresh dairy, rabbit or chicken manure, fruit and vegetable waste, and garden trimmings. If piled without bulking agents, energy materials are too wet and dense to allow much air into the compost pile. If you have too many energy materials, you may detect a rotten egg smell. Some raw materials contain a balance of energy and bulking agent properties. These can be ground up tree and shrub trimmings, horse manure and bedding, deciduous leaves and legume hay. They will compost readily by themselves, and can be added to an existing pile to ensure the success of a hot compost pile. Use a combination two parts by volume bulking agents with one part energy source. You can test compost for weed seeds by mixing several quarts of the compost taken from various parts of the pile with potting mix in a 1:1 ratio and spreading it in flats. Keep the flats warm during the day and cool but not cold at night. For example, run the test inside in the winter, outside in the summer and in a cold frame during the spring or fall. Water the flats regularly, and observe any weed seedlings that emerge over the following two to three weeks. This test will usually show if weed seeds are present, but it may not accurately predict their density, since some seeds may be dormant.

Q. Why do my spruce trees have brown, dried-up swollen tips on the green branches? — Joe, Rosendale

A. This may be Cooley spruce galls, Adelges cooleyi. This species is a small black, soft-bodied insect. Females may be winged or wingless. The gall it forms on spruce is an elongate, pineapple-shaped green growth that develops on the tip of the current year’s twig. In late summer these galls turn brown. This species has a complicated life cycle that involves five biological forms of the insect, three of which occur on spruce and two on Douglas-fir. It requires at least two years to complete all five forms on both host plants. This pest can thrive on Douglas-fir alone by continuous reproduction of two forms, with as many as five to six generations produced each year. However, it appears that those forms occurring on spruce cannot continue producing indefinitely and need to find the second host, Douglas-fir, to complete the entire life cycle. On spruce, this key pest overwinters as immature females at the bases of terminal buds. Females resume feeding in the spring, mature and lay several hundred eggs on lateral twigs. Eggs hatch in 10-14 days into young nymphs that migrate to new growth and feed at the base of needles. Their feeding causes abnormal plant cell development forming a gall that soon surrounds them. These life stages remain in chambers inside gall tissue throughout the summer. By mid-summer galls brown, dry out and adelgids emerge from the opened chambers. They migrate to Douglas-fir or remain on spruce. On spruce twigs, galls are formed in response to feeding by this pest. When infestations are heavy the resulting bud destruction may destroy the shape of the tree. On Douglas-fir, heavily infested needles appear to be covered with snow. No galls are formed on Douglas-fir, but feeding by this species on the underside of needles may cause needle discoloration, needle distortion and premature needle drop. When practical, remove green-colored galls on spruce during June or July, before adult adelgids emerge to manage infestations on a few small trees. Apply registered insecticides according to label directions to spruce from mid-September through early October to manage overwintering immature females. A second alternative is to apply registered products in the spring before bud break just before the females mature and lay eggs. Douglas-fir can be sprayed in April just prior to bud break, or during mid-September through early October, to manage overwintering immature females. Pesticides are poisonous. Read and follow directions and safety precautions on labels. Handle carefully and store in original labeled containers out of the reach of children, pets and livestock. Dispose of empty containers right away, in a safe manner and place. Do not contaminate forage, streams or ponds.

— Dona M. Crawford is the community horticulture educator for Cornell Cooperative Extension of Ulster County.