What does it mean when newly purchased commercial compost smells strongly of ammonia? The compost I’m talking about is 2 yards worth and it has been delivered; I’m stuck with it. Will it improve or hurt the soil I intend to combine with it? And should plants get near it? This is serious. I have obtained all new plants and prepared everything for a new bed…but I’m not going ahead with this because of the amount we’re dealing with.
According to Ann Lovejoy’s October 16, 2003 column from the Seattle PI, a strong ammonia smell indicates “immature” compost that could harm plant roots.
Compost facilities sometimes have bad batches with too much nitrogen in the original mixture of clippings, compared to the amount of carbon, and it can be solved over time by adding “carbon-rich materials such as leaves or [finely ground] wood chips,” according to a compost odor factsheet produced by Resource Recycling Systems, Incorporated. Acidity can also be a factor–less acidic mixtures sometimes remain immature until more acidic ingredients (such as leaves or needles) are added.
If you haven’t already contacted the company, you might try that. At least one local company stands by its compost with a satisfaction guarantee, and that fact may encourage whoever sold you this compost to make things right for you.