Should I Burn Weeds With Kerosene?
Q: I have a rather large asparagus bed with weed issues. I have regularly burned the bed in late fall when the foliage is dead. However, sometimes the fire does not seem to be hot enough to do its job. What are your thoughts about using kerosene in a sprayer to assist in a burn?
A: I was astonished to discover that there are gardeners who do this. Before your inquiry, I had never heard of using kerosene to burn weeds in asparagus. For many reasons, I don’t recommend it. Do this instead: harvest asparagus by snapping seven to nine-inch spears with tight tips. You can do this regularly for two or three weeks in spring. Stop the harvest when the diameter of most of the spears become less than three-eighths inch.
At this point, snap all the spears off at ground level. Apply one-half pound of ammonium nitrate fertilizer per fifty feet of row. Since no asparagus greenery is aboveground, spray the patch with herbicidal soap. This will kill any existing weeds. New spears will emerge, fern out, and provide a large canopy to cover the space between the rows. Once a dense fern canopy is formed, weed growth will be shaded out.