[header] How to get rid of foxtails [title] Use glyphosate or similar products. [step] Broadleaf fertilizers will not work against foxtail since foxtail is a grass. If you want to use chemical control methods, you should look for an herbicide that can kill grasses. 
One of the most easily accessible types is a chemical called glyphosate. [substeps] Glyphosate is a non-selective herbicide, so it will kill just about everything in the area you apply it in.