My cold weather herbicide spray comparison using dandelions was started November 12. The temperature was 34 degrees, soil temperature 33. Speedzone was most effective and T-Zone was almost as effective. Surge, 3-way, and Quicksilver were less effective, after 10 days with temps mostly in the 30's to 40's. Glyphosate as Lesco Razorburn was slow, but browned the grass spot after 8 days. Cold weather seeding was up to about one-inch tall at 27 days. The plot where seed was raked in had the best germination.