Milorganite is made from the sludge from Milwaukee's waste treatment plant. It is heated to a level that kills harmful pathogens and some type of thickener is added to make it form pellets when it dries so that it can be spread using any lawn spreader. But there are some things that make it stand apart from chemical lawn fertilizers.

• Doesn't Burn
• Won't Easily Leach from Soil into Water Supply or Canals/Lakes

Won't Burn
The reason chemical fertilizers burn is that when they break down to supply your lawn with food they leave behind a type of salt. Although this salt is not sea salt or table salt it amounts to the same as spreading table salt over your lawn every time you fertilize. The recommended quantity of fertilizer you spread is just a little below the amount that will hurt your lawn. Spread too much and your lawn is severely damaged by too much salt.

Miloorganite is NOT a chemical fertilizer and therefore does NOT leave salt as a residue. It is a slow release, natural food in a pelletized form. It would be extremely difficult to apply so much that your lawn would be damaged.

Doesn't Leach
One of the biggest (in my opinion) causes of pollution to our water ways is fertilizer run off. We have a lot of rain in the summer which creates a constant flow from our lawns into our waterways. Chemical fertilizers are dissolved and carried out to sea through our canal sytems in huge amounts. Algae's favorite food is the same as our lawn's so algae thrives in this food filled water. Algae is meant as a natural filter of water but when we add all that extra food, for it to eat, it over populates the water. Since algae uses oxygen to digest this food it uses up too much oxygen from the water which the fish, crabs, oysters and other sea live need to survive. Our water turns sour, red tide (a type of algae) thrives, our beaches become uncomfortable places to be and sea life dies.

Milorganite, by it's very nature, is a natural, slow release source of nitrogen, phosphate, calcium and iron. It is slow to dissolve in water because it needs to be broken down by the natural organisms in the soil before it is useful to your lawn or algae. Heavy rains only carry off the small amount that has already broken down (an amount that would be normally present if we were not), at least that is how I understand it.

Home Depot carries milorganite and it's cheap.