The Q&A Archives: Wood Mulch And Nitrogen Depletion

Question: Ortho Online says that "When used as surface mulch, fresh wood doesn't deplete nitrogen supply as it does when worked into the soil." Univ. of Missouri Extension online says much the same thing. Others, including a response given in your Q&A seem to indicate that nitrogen must be added even to a surface mulch. Who's right?

Answer: We all want to be right! Guess it's a case of how quickly the mulch breaks down, as to whether or not it depletes the soil of nitrogen. If you're using fresh sawdust, it wouldn't hurt to use a cup of nitrogen per 100 square feet of mulch material, to ensure that the decomposing wood doesn't take its nitrogen from the soil. To settle the entire question, how about piling up the fresh material and allowing it to decompose slightly before using it in the garden?

« Click to go to the homepage

» Ask a question of your own

Q&A Library Searching Tips

  • When singular and plural spellings differ, as in peony and peonies, try both.
  • Search terms are not case sensitive.

Today's site banner is by Marilyn and is called "Southern Comfort"