Milorganite’s slow-release nutrients are available as plants need them. There’s no immediate, excessive release of nutrients after fertilizing, which causes a flush of growth.
At least 80% of the nitrogen in Milorganite is water insoluble (slow release) and is delivered to the roots through microbial activity in the soil, but the conditions need to be right. Microbial activity occurs when soil moisture is adequate and soil temperatures are 55–85 F. The microbes break down the nutrients from Milorganite making them available to plants. When conditions aren’t favorable, Milorganite’s nutrients stay right where they are until there’s enough water and the temperature is within range.
Slow-release nutrients, like those in Milorganite, are gradually available for up to 10 weeks, which means fewer applications. This extended feeding provides more uniform growth, a deeper and better-established root system, and a healthier lawn and garden. Slow-release nutrients are also better for the environment because the nutrients are less likely to leach into waterways.