The right choice

Compared to fast-release, controlled release is an expensive option, but it can be worth it. And there are certainly plenty of products to choose from.

“Every supplier has a different way of releasing nitrogen now: timed release, slow release, controlled release,” says Mark Grunkemeyer, owner of Buckeye EcoCare in Dayton, Ohio. It can be hard to keep up with it all.

So what are your options?

Slow release fertilizer: The components of the fertilizer are converted in the soil by microorganisms or physiochemical effects. This can mean that the process is dependent on the weather, just like plant growth so it can release at the times the plant needs it.

Controlled release fertilizer: Nutrients are packaged in coated granules that are released through the coating over a period of time. This can depend on the temperature – e.g. higher temperatures accelerate nutrient release while lower temperatures delay it.

Stabilized release fertilizer: A substance like a nitrification inhibitor is included in the fertilizer. This substance keeps the nitrogen in the soil longer.