To properly use a flame weeder, first make sure that that area is safe for flame weeding. It should be free of dry, flammable material as well as desirable grasses and garden plants. Do not use a flame weeder in drought-stricken areas or regions prone to wildfires.
If you’ve determined a flame weeder is the best tool for the job, follow manufacturer instructions for use, water the area before flame weeding, and pass the weeder briefly over the weeds (flame weeders can kill weeds in under 1 second). Flame weeders can also be used to destroy the seeds of invasive weeds, which weed killer sprays cannot do. Once you’ve completed flame weeding, test the leaves of the weeds exposed to the heat. If light pressure leaves visible thumbprints, the flame weeder has successfully killed the weed.
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How to Use a Flame Weeder: 7 Easy Steps
Flame weeders are a natural alternative to weed killer sprays and soil additives. They leave no trace chemicals in the soil and wipe out weeds in seconds. Many weeds exposed to flame weeding will die down to the root within days, although well-established perennial weeds may require repeat flame treatments over 2–3 weeks. When flame weeding, follow these simple steps.
Is a Flame Weeder the Right Tool?
Flame weeders are a powerful, natural way to destroy weeds, but they perform better for some applications than others. Before flame weeding, it’s important to evaluate if it is the best method for your lawn and garden.
Best Uses for Flame Weeders
- Killing weeds growing in gravel, pebbles, concrete, or asphalt.
- Killing weeds growing in gardens with few desirable plants or where desirable plants have not yet sprouted.
- There is a very low chance of setting fire to any nearby organic material.
- The region is not prone to wildfires.
When to Avoid Flame Weeders
- Weeds are growing among desirable plants in an established garden or lawn.
- There is a risk of setting fire to structures or organic material.
- The region is currently experiencing drought conditions.
- The region is prone to wildfires.
Take Safety Precautions
When using a flame weeder, always follow manufacturer safety instructions for fueling, lighting, and operating your flame weeder. Wear protective equipment as necessary and be sure to prevent the flame from contacting structures, people, animals, or elements of the flame weeder itself (such as fuel hose and tank).
When used properly, flame weeders are very safe and efficient weed control tools. Despite this, it is important to keep in mind that propane burns at over 3,500℉ (1,900℃). Precautions must be taken when operating a flame weeder. Check with your local fire authority before using a flame weeder. If there is a high wildfire risk, it may not be legal in your area.
Water the Weedy Area
Although it may seem counterintuitive to water weeds before using a flame weeder, it’s a good idea to thoroughly water any area before you begin flame weeding. Use a garden hose or sprinkler to douse plants and soak the soil. This will prevent any unwanted flame damage and protect it from fires. Don’t worry, any weeds exposed to flame weeding will still be killed.
Preserve Desirable Plants
Flame weeders work not by burning weeds but by heating the leaves of the plants up to at least 160℉ (65℃) to destroy plant tissues and cause wilting and death. Because flame weeders are so hot, they can often destroy plants 6 inches or more from the flame nozzle.
If you are working in a flowerbed, lawn, or garden, with desirable grasses, keep the flame weeder at least 12 inches from any plants you do not wish to damage. Because flame weeders can kill plants in under a second, they are best used in areas without any desirable plants, gardens where your desirable seeds have not yet sprouted, in pavement/gravel, or in overgrown areas.
Kill Weeds in Under a Second
Flame weeders kill plants in 1/10 of a second by superheating the air near the plant and destroying leaf tissues. You should not actually set fire to a weed or linger near it to kill it. When flame weeding, walk slowly along your garden row or edge of your driveway, passing the flame wand 3–6 inches above the weeds. The hot air will lethally damage the weeds. Within hours, the plants will wilt and begin to die.
If you see steam or smoke rising from plants as you flame weed, this is a sign that you are lingering too long and may cause plants to catch fire. Increase your walking speed and/or the distance between the flame and the weeds. Flame weeders work fast, killing weeds almost as soon as you pass the flame above them.
Destroy Weed Seeds
One massive benefit of flame weeders over weed killer sprays is that a flame weeder can kill unsprouted weed seeds. Simply pass your flame above weed seed heads or portions of ground covered with invasive weed seeds, such as goat’s head burs. The same temperatures that kill weeds will also destroy most seeds. You might even hear small popcorn-like crackles as the superheated air evaporates the moisture inside the seeds, destroying the seed kernel.
Within 1–4 hours after flame weeding, you will see the effects of your work. Weeds will still be green at this stage but should have taken on a dull, wilted look. Pinch leaves of flame-weeded plants lightly between your thumb and finger. If there is a dark, visible thumbprint, the flame weeder has done its work.
Within 3–7 days, these weeds should have browned and shriveled completely. For small weeds, under 4 inches tall, one pass with the flame weeder typically kills the weed down to the root. More established weeds may require repeat flame weeding treatments if they attempt to sprout new leaves.
When Should You Burn Weeds with a Flame Thrower Weeder?
You should use a flame thrower weeder to kill weeds if the weeds are located in an area suited to flame weeding. Flame weeders are best used on weeds in the following situations:
- Weeds growing up through the gravel.
- Weeds growing through cracks in concrete or asphalt.
- Weeds have completely overtaken a yard or garden.
- Weeds are growing in an area where desirable plant and grass seeds have not yet sprouted.
Always take precautions not to use flame weeders in areas where there is high fire danger or risk of setting structures or desirable plants on fire. Keep in mind, flame weeders work by superheating the air near plants to kill them. Burning weeds is improper use of a flame weeder. That said, there is still a risk involved in using a flame weeder on dry or flammable vegetation.
Does Flame Weeding Kill Weeds Permanently?
Flame weeding often kills weeds permanently. Young weeds under 4 inches high are usually killed by a single exposure to a flame weeder. Additionally, flame weeders typically kill annual weeds (such as chickweed) permanently.
Deep-rooted perennial weeds (such as dandelions) may grow new leaves in the weeks after flame weeding has destroyed all visible growth. In these cases, 2–3 flame weeding sessions should kill these weeds as well. If the plant is continually prevented from growing new leaves, it will eventually spend all its stored energy and die.
How Close Can a Flame Weeder Be to a Plant?
A flame weeder can be 3–6 inches from a plant to work safely and effectively. The hot air created by burning propane is what kills the plant, not the flame itself. Do not use a flame weeder to set fire to weeds or plants, as this can create a fire hazard and release toxic fumes from some plants (such as poison ivy). By keeping the flame a few inches from the plants you wish to kill, you will wipe out weeds and keep yourself safe.
Does Flame Weeding Kill Seeds?
Flame weeding is the best way to kill weed seeds. When weed seeds are exposed to temperatures of 160℉ (65℃) or greater, they are destroyed. The superheated air from a flame weeder’s propane flame works like a microwave on a popcorn kernel. The seeds are heated in under a second, causing moisture inside the kernel to expand violently, destroying the seed from the inside.
Emergent herbicides kill growing weeds but leave weed seeds unharmed. Pre-emergent herbicides only kill weed seedlings as they begin to sprout. Flame weeders are the top garden tool for killing weed seeds.
Is Burning Weeds Bad for the Environment?
Flame weeders are not dangerous to the environment because they are not used to actually burn weeds. Plants are killed by being exposed to the heat of the flame weeder, which causes them to wilt and die without catching fire. Since you won’t be burning weeds when you flame weed, you won’t be creating harmful smoke and fire.
Flame weeders are safer for the environment than herbicidal chemicals that may pollute soil and water supplies. The sole emission of flame weeders is burning propane. Because modern flame weeders are very efficient, they use propane at a small rate and carry a less negative impact than using herbicides.
Killing Weeds with a Flame Weeder
Flame weeders are fast, efficient tools for killing weeds. By passing a flame weeder over a weed, the plant reaches temperatures of over 160℉ (65℃), which destroys plant tissues and causes the plant to wilt and die within hours.
Use a flame weeder to easily remove weeds from sidewalks, driveways, or gardens free of desirable plant life. A flame weeder wipes out weeds without leaving any residual chemicals in the soil or water supply, meaning you can flame weed an overgrown garden one day and plant a new crop the next day.
Always take proper precautions when using a flame weeder to keep yourself, your home, and your desirable plants safe. When used properly, a flame weeder can be your best friend for getting rid of weeds quickly, the natural way.