Burning The Competition

By: Andrew Price FAIH RH0004 (Photos: Andrew Price)

Weed growth is a valuable indicator of the health of the landscape. Weeds tell you so much about the potential of the site and should be given your full attention.

In cultivation I get much joy from the “happy accidents” of a plant coming up in the perfect spot that makes my job so much easier, plus the client essentially gets a free plant. Unfortunately a majority of weed growth is unwanted and antagonistic to the cultivated garden, which is why weeding is such a necessary albeit overwhelming task.

Chemical control has so many biological drawbacks without even factoring in operator safety, plus you are left with the ugly dead shell of the weeds that need removal anyway.

I have been experimenting with weed burning for several years now and consider it the best method of control for a number of reasons:

  • Easily eradicates seed growth that would be impossible to remove without the patience of a saint.
  • There is nothing to remove from site except your memory of what was there.
  • The temperature removes the biological signature and seeds left by the weed residue allowing new species to establish.
  • Your hands stay clean and warm – great on a winter’s morning.
  • This makes weeding fun and quick not something that gets put in the too hard basket. An employee of mine had an apt saying “If it is fun it gets done”.
  • I regularly quote a line from Apocalypse Now when using this weed control method which is “Terminate with Extreme Prejudice”.



Now before you go setting your weeds ablaze and perhaps causing a runaway fire that will not look good on your CV, please consider that this is a skill that has to be done with thought, care and caution. This is not a job relegated to an employee that would be outwitted by a box of hammers.

Like anything that sounds too good to be true there are limitations to the effectiveness of this method, there are some species of weed that will need regular treatments before it gives up the fight – dandelions and onion weed are prime examples.

Species that it works best on are Flickweed/ Hairy Bittercress (Cardamine hirsuta), Spotted Spurge (Euphorbia maculata) and Winter Grass (Poa annua) – with a name like that it is no surprise that it hates being burnt. Interestingly Ficus species (F. macrophylla & rubiginosa) that come up in walls are easily killed plus wayward Ficus pumila shoots and stems are eliminated with extreme prejudice.

Another good trick is to pull the weed out by the roots if it is large or has the potential to regrow and burn the root stem or tuber, which gives most plants a death sentence. The trick is to get them when they are young as they are a smaller target. Larger weeds are normally slashed down with a whipper snipper then burnt at ground level; a repeat treatment a week later normally forces it off this mortal coil.



I hate clichés like the plague but one teaspoon of prevention is better than a pound of cure.

Be prepared to have your insurance updated by the good people of Fitzpatricks with a runaway fire clause listing the risk minimisation measures you have in place e.g. fire extinguisher on hand, site preparation, weather monitoring etc. Never use this method on dry windy days with a high fire risk!

Sweep paths and gravel of leaves to negate flare-up hazards, being especially careful with highly flammable leaves like Eucalyptus. Ensure that there has been no fuel or oil residue on paved areas.

Wet the soil and mulch before attempting to wilt weed growth and treat only in cool still conditions with watchful care of any ember activity. Be sure to go back over treated areas and check for any smoke activity. If in doubt use a pump sprayer to wet any spots that might reignite with a sudden gust of wind. If you are prepared and of sound mind you will find that the norm is a weed free garden and when they do gather the courage to germinate you almost pity their fate.

I have experimented with a variety of butane guns but my favourite is found in the tool section of Bunnings that will cost you $40 with enough change for a small chocolate bar.

Be safe and enjoy the smell of burning weeds in the morning!


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Thank you for this article. I am not sure how long ago this was published but it gives me some hope about killing off our onion weed. Do you just singe the leaves and until it burns back or do you have to get to the bulbs?

Thanks you

Hi Debra, thank you for your comment, burning off the foliage of onion weed is a great way to suppress this plant but the best strategy is to out-compete this weed using plants that prevent light from reaching it. I have many onion weed populations in gardens that I maintain that are regenerating less and less because I make life very hard for them.

Onion weed tends to put on a growth surge on the cusp of each season so I’m watchful to burn out any regeneration I notice. Hand weeding unless you are every skilled only encourages this bulb weed. A Japanese weeding Knife called a Hori Hori is much better than using a standard trowel, plus you can grind the bulbs into a paste then burn them – they are very unlikely to survive.

Keep up the fight!

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