North American Fruit Explorers mailing list at ibiblio

[Alan Haigh <alandhaigh@gmail.com>]

Anecdotal evidence can be pretty convincing when it is repeated hundreds of times over decades of experience with plenty of comparisons in the field, but it is admittedly much more convincing to the observer than to the person down the line hearing about it, and it should be.   Nevertheless this discussion might be useful if someone is inspired to investigate further.  Meantime, I suggest running with the cheapest effective mulch you can find. 

 

The quality of pine needles being hydrophobic is an interesting point.  I've always assumed that this was a tactic of pines to keep competitors from sprouting under the needles.  Under white pines the litter is so thick and dry- right down to the later stages of decomposition- that not much has a chance to germinate beneath the tree.

 

I believe that there are advantages and disadvantages to a mulch being hydrophobic, and while during drought course wood chips (the kind that comes out of a chipper, not a shredder) will require more water to reach the roots of plants than pine needles, the water in that wood will wick into the soil when the soil becomes dryer than the chips.  In other words, the chips act as a reservoir, in my opinion.  During drought it may be advantageous to push away the mulch before a quick thunderstorm, but a drenching rain that soaks the chips and the soil beneath will extend the amount of available water.  The intense worm activity under wood chips allows even several inches of rain over a few hours to effectively drain into the soil.

 

OK, this is largely theoretical, but I have a nursery with hundreds of trees and an entirely inadequate well to provide sufficient water to get me through droughts.  I watch where the fine root hairs go and when they're white, I know there's sufficient moisture.  There's no payback in my researching this as I run with the cheapest available mulch- these days it's mellowed stable waste (urine soaked soft wood shavings and manure) which I get very nearby, loaded on my truck for free and sometimes mulch hay which I have to pay for but is less labor intensive to use.  Still, I would love to see some legitimate data as well- just not enough to do the work.