Ok, I need some advice. I want to fertilize my lawn, but I'm not sure if I should do it now in the fall, or wait for the spring. I'm in Canada and it gets cold here (around 15Deg F/ -10 c) during January and February. So I don't know if a fertilizer would work now or not. This may be fairly standard knowledge to most of you, but I'm not use to having a big lawn, and I don't want to make a big mistake.