We live in a homeowner’s association with a covenant about the percentage of mulch (organic/wood) we can use compared to rock. It only allows 25% of our landscaping to be wood. They claim that wood mulch is home to rodents of all kinds. We prefer wood bark. Is there a publication I can use to argue our case?

All mulching materials have advantages and disadvantages. Research did not yield any documents that make a watertight case for or against any of them, including crushed rock, lava, etc. Here are some frequently mentioned concerns:

1. Rock mulch such as …