After spending nearly $100 in BurnOut to kill 800 s.f. of lawn, I have to report that it is a bust. I have new grass growing in, but worse, is that it did not kill the Buttercup weed (which it touts it will kill). I’ll have to check to see if it has killed all of the viola. So it appears that if I cannot find the 20% vinegar solution that I may have to resort to something like RoundUp combined with CrossBow (what is recommended by our county agent to get rid of non-natives). Ick. I hate using chemicals in my garden. The only way I can justify this is that I have tried the best alternatives and only plan to do it once.
To be clear about how I used the BurnOut, let me state that my first purchase of about $40, was for a gallon of the stuff premixed and ready to spray. I sprayed on an afternoon that was about 80°. The directions say to keep the area dry for at least several hours, which I did. Early the next morning, my sprinklers went on for about 10 minutes. I allowed this because it was going to be another warm day and the lawn sprinklers also water the surrounding plant borders. After at least 5 days of warm weather, it was clear I needed to spray again. When I returned to Portland Nursery to get more, they told me that it is normal to have to reapply organic weedkillers to be effective. This time I purchased the concentrated formula that I would need to mix myself. It was almost $60 for this. The suggested mix ratio is 1 part BurnOut to 2 parts water for the greatest effectiveness. I mixed 3 batches to this ratio and sprayed 2 of the batches on the worst areas of the lawn. The rest I used in some gravel path areas that had weeds. What you see in the photo is after 3 days of warm weather and one day of cool weather resulting in rain. The irrigation system was turned off before the latest round.