North American Fruit Explorers mailing list at ibiblio

[Alan Haigh <alandhaigh@gmail.com>]

Jim wrote, "As a retired chemist, I appreciate your experiments and respect your results.
But as a gardener, I have observed that "acid-loving plants", such as holly, azalea, and blueberry all thrive well when mulched with pine needles..."

 

Well, I have also noticed that they all thrive under a hardwood mulch as do most other woody perennials.  If you're interested in theorizing what it is about pine needles that make them a superior mulch to something else you better try some experiments using both.  

 

Blueberries suffer from drought, holly and azalea suffer from winter dehydration so I would assume most any mulch would be helpful.  I would put my money on wood over needles, though, because rottting wood holds much more water than pine needles and also encourages more earthworms.