How long does it take to get aged cut grass clipping that I could mulch w/ on the garden?

Asked May 31, 2015, 8:17 PM EDT

Is it a full year? Would the grass clippings age quicker, in a closed black plastic bag or just out in the environment? Thank you

Baltimore County Maryland

1 Response

Warmth and moisture will make them decompose more quickly. Once they decompose they will be more of a soil amendment than a mulch. The plastic bag would speed up the process in cooler weather especially. If you want to use them as a mulch to suppress weeds, you can use them immediately. They will use a little nitrogen as they decompose, so you can sprinkle a little nitrogen fertilizer on them.

A thick mulch of fresh purely grass clippings (no brown--i.e. carbon-- materials, such as dead leaves), may have an unpleasant odor as they decompose. To prevent that, mix in a little brown material (straw, dead leaves).

See our publications on mulch and compost in the Publications section on our website.