By Bob Fiorello, San Francisco Recreation and Parks (originally posted 4/26/2010)

As children, we learn through instruction and observation to both respect and appreciate the awesome power of fire. Likewise, we are also taught at an early age “not to play with fire” for fear of getting hurt- or burning down the house. Fire is undoubtedly one of mankind’s greatest tools, but as we all know too well in the West, it can be a devastating, destructive force as well. So if you’re considering adding flame-weeding to your IPM arsenal, think carefully before deciding whether it’s the right method for you. Hopefully this three part blog exploring this hot topic will be of some value to you to that end.

The use of fire in habitat modification has been with us a very long time. The innovation of controlled or prescribed burns to manage land dates back centuries in Native American culture and remains an important, yet controversial, forestry and rangeland practice. These conservation measures differ considerably from the detrimental slash and burn approach to agriculture still used around the world today. Yet, neither of these methods are what we are referring to when discussing flame-weeding, or green-flaming. Flame-weeding uses fire to quickly sear or cook weeds. It’s an old technique that is becoming increasingly popular and more sophisticated with time. The question remains however, is it a useful and appropriate IPM technique for our parks? The answer to that question (like so many that relate to public lands) can be kind of complicated, but clearly worth exploring.

First of all, before even considering whether to authorize taking what amounts to a torch to the beloved town square, park managers want to be assured that green-flaming is both safe and effective. Convincing One’s boss of this can be tricky since flame-weeding is inherently risky and a positive outcome is really operator dependent. Sure, you can say the same thing about spraying herbicides. That’s true, but even in the worst case scenario, it’s hard to imagine how applying Roundup could result in burning down a gazebo. Garlon and Turflon do possess all that kerosene…but still. Let’s face it, burning weeds can, and in some rare cases, does result in accidental fires- all be it small and manageable fires. The bottom line is that, in terms of safety, proper training and fire prevention measures must be in place prior to starting any green-flaming program.

So, Safety First- that can surely be dealt with and later we’ll get into what’s required and recommended. That leaves us with the other burning question pertaining to the overall effectiveness of the technique. Does green-flaming really control weeds? Or is this a matter of, well, smoke and mirrors? The method does clearly work (for some situations at least). In other cases it’s the ideal solution to the problem. Is it worth the hassle of purchasing the equipment, setting up a training program, obtaining permits, and dealing with the literally explosive issue of propane tank storage? For many of us in the West, the answer is probably YES! Whether or not weed-flaming is a successful component of your park district’s IPM program comes down to the details.

We’ll be getting into all that and more in the next two posts so stayed tuned. In the meantime check out the videos about this very topic at eXtension.org. Click on this link www.extension.org/article/18329 or simply put “Weed ‘Em and Reap video” in your search engine. Please note that eXtension.org is an interactive learning environment delivering the best, most researched knowledge from many of the nation’s leading land-grant universities. It’s a great site and well worth your time. Also, to learn more about flame-weeding and other non-herbicidal weed control strategies for western parks check out NCAP’s four part series on the subject at www.pesticide.org/pfp/reports.html. If you’re in a hurry, check out NCAP’s two-page fact sheet on flaming at www.pesticide.org/pubs/alts/pdf/flameweeding.pdf. NCAP, the Northwest Center for Alternatives to Pesticides is a proud sponsor of SPIN.

Click on the following links for images of flame weeding: flameengineering.com, and www.househacker.com