How long does dog poop take to decompose?
About nine weeks in summer, far longer in a Missouri winter, and decomposing is not the same as going away.
Roughly nine weeks in warm, damp conditions. Considerably longer in cold weather, and in a Missouri winter it can sit essentially unchanged from December until the ground thaws.
That range is wide because decomposition depends on temperature, moisture, soil contact and how much there is. A pile on bare damp soil in August breaks down far faster than the same pile on frozen grass in January.
Why winter is different
Below about 40 degrees the soil bacteria that do this work mostly stop. Material that lands in December is still there in February, preserved rather than decomposed.
This is the mechanic behind the spring thaw problem. Three months of accumulation does not break down gradually through the winter, it waits, and then it all becomes visible and active within about a week of the ground warming. Customers who have never thought about their yard in February call us in March.
Decomposed is not gone
This is the part that matters more than the timeline.
When waste decomposes, the visible material disperses into the top layer of your soil. What was in it goes with it. The nitrogen and salts that burn grass are still there. So are the pathogens, and roundworm eggs can stay viable in soil for years regardless of whether anything is visible on the surface.
A yard where everything has broken down is not a yard that has been cleaned. It is a yard where the contamination has been spread out and made invisible.
That is worth knowing if the plan was to let nature handle it. Nature does handle it, in the sense that the evidence disappears. It does not remove anything from your property.
What this means practically
If you are clearing a yard that has gone a season without attention, expect the job to be larger than it looks. Some of what is there has partly broken down and comes apart when it is picked up, which slows the work considerably compared with a yard cleared weekly.
It is also why we quote a neglected first cleanup separately rather than at the regular rate. A yard with three months on it is a different job from a yard with seven days on it, and pretending otherwise would mean charging everybody for the worst case.
The short version
Nine weeks or so in summer. All winter in Missouri. And at the end of either, the material has moved into your soil rather than left your property.
