How Long for Milorganite To Work?

Yet another Dear Reader question from my search results.  I can't remember if I covered this before, but it bears repeating anyway.

Milorganite has some water-soluble nitrogen, and definitely has a lot of water-soluble iron, so you might notice some change in 72 to 96 hours after irrigation or rainfall.

However, the organic nitrogen and biological effects won't be seen for at least three weeks.  Even then, they're not the sudden green-up of synthetic fertilizers.  Slowly, over time and with continued use, the lawn will continue to look better.

Organics are not a fast cure, which is actually good.  We don't want them to be.  Fast cures tend to also peter out quickly, whereas the organic fertilizers you're using will be slowly improving your lawn and gardens for years to come.