Organic materials are fast becoming the preference for use in lawn care treatments. In this case, organic lawn treatments are defined as any materials placed on the lawn which are incapable of doing harm to the microbes living in the soil which naturally break down nutrients for grass and other plants to absorb. Not only are organic lawn treatments less expensive, many of them can be made at home.
Rubbing alcohol is a poison to most insects when consumed, so it works well against pests trying to eat the lawn. Nicotine kills insects too; they absorb it through the skin, though it can kill peppers and tomato plants, so it should only be used on the lawn. Steep 1 cup of tobacco in any form in 1 gallon of water overnight. Strain out the tobacco and add 1 cup of rubbing alcohol and 5 tbsp. of dry laundry soap powder or flakes. Spray the mixture across the lawn; the soap maintains a high viscosity, which keeps the mixture on the leaves longer so it can act to kill insects more effectively.
The Bordeaux mixture is a fungicide used in vineyards since the 20th century. Make it by dissolving 1/3 lb. of calcium hydroxide in 1 gallon of water. Soak a lump of copper sulfate in it overnight. Strain mixture and spray it over the lawn. The reason this works is that copper sulfate is a heavily ionic compound. The calcium hydroxide breaks loose many of these ions, which reattach to the first thing they come across, typically a specific enzyme shared by all fungus. Since the enzyme in the fungus is bound, it cannot reproduce or grow, and it dies.
Organic Lawn Fertilizer
The basic nutrients your lawn needs to thrive are nitrogen, potassium, and phosphorous. Alfalfa has 2 percent nitrogen, 0.5 percent phosphorous and 2 percent potassium. Bloodmeal contains 12 percent nitrogen, 1.5 percent phosphorous and 0.6 percent potassium. Bat guano 8 percent nitrogen, 5 percent phosphorous and 1.5 percent potassium. Combine them in a 3:2:1 ratio. Thirty pounds will cover 1,000 square feet. Water it lightly into the lawn to keep the wind from carrying away some of the bloodmeal. It will provide all the nutrients the lawn needs for the year.