I was reading the Colorado State University Extension Office article on lawn care and it says that 75% of lawn's nitrogen needs should be supplied in the fall and that fertilizer with 25-5-5 should be used. It also recommends using Urea fertilizer 46-0-0 at 2lbs per 1000 sq. ft. Or ammonium sulfate (18-0-0) at 5 lbs/1000 square feet.
I have resisted the notion that grass needs an extra heavy dose of nitrogen in the late fall; however, the evidence is going hard against me. The heavy dose in the late fall seems to carry the grass longer into the winter and bring it out of dormancy earlier in the spring. I've seen one lawn in Pennsylvania only remain dormant for a total of 2 months in 2 winters.
Certainly the easiest way to go is the CO state suggestion. If you want to try it with organics, then apply corn gluten meal at a rate of 20 pounds per 1,000 square feet twice or three times in the late fall. Corn gluten meal has the highest protein content of all the organic fertilizers. Grain protein translates quickly into plant food (3 weeks).
second on corn gluten meal. Applying in fall will act also to prevent germination of crabgrass and dandelions. A generous coating of organic or good yard waste (low on wood products) compost is a gentle way to feed your lawn in the fall. Here in CO, your lawn should be starting to brown out with this heat. bluegrass and rye are cool season grasses. Continue to water them deeply, and less often than most people. They will green up again in the fall when the daytime temps break back to the 80s. That is also a premiuim time to reseed. Chemical fertilizers can set the stage for other problems like mold, fungus and some weeds. theyre really just salts. Try the corn gluten, or blood meal if you want to apply nitrogen.
posted 8 years ago
Rich adds an interesting point about blood meal. Blood meal is extraordinarily high in available nitrogen in the form of blood protein. When it gets wet the protein is decomposed immediately and can burn roots killing the plant. However, it is well known that grain type fertilizers are "slow release." I hate the terminology but we live with it. It actually releases to the microbes immediately but it takes 3 weeks of microbial processing for the protein in the grains to become plant food for the grass. But blood meal becomes available over night. If you want a quick shot of nitrogen, nothing is faster than blood. Obviously you don't want to kill your lawn, so if you decide to use blood meal, I would mix it thoroughly into the bag of corn gluten meal at a rate of 5-10 pounds of blood to a 50-pound bag of grain. Then apply the contents of the bag at a rate of 20 pounds per 1,000 square feet. That should dilute the effect of the blood on the roots. Then, immediately water the fertilizer in. What you do not want to have happen is the morning dew to be the first dilution of the blood meal. The dew does not have enough volume and will create a strong solution of blood that can backfire and kill the grass. Water to dilute the blood and wash it into the soil.
Companion Planting Guide by World Permaculture Association