I've read that red maple leaves raise Ph. Some sort of CaCO residue

I don't buy it. Does the info seem reliable and research based? The only problem I could see is tying up N. which shouldn't really be an issue for established plants with roots far enough from the surface or if you provide some supplementary N.

I expect the mulch would have no affect on your pH but would increase the plants access to iron just by virtue of the decomposition process which releases humic acids. That last is just an opinion, however.

Harvestman, I am skeptical as well. But not enough so to put my plants to the test. The info is stated as a simple one line something to the extent "beech and maple leaves and wood have been shown to retard blueberry growth"

I come up with it from several extension sites like cornell and URI as well as some others. But it definitely has the feel of one of those statements that got put out there and then just copied over and over again. None of them give footnote or reference to the source or reasoning. All of these sites do recommend mulching with wood and do point out that additional N may be required when doing so.

Noogy, I will look into the pH and see if I can find anything...now I am curious.

The only other reference I bumped into was in regards to Anthocyanin (one of the red pigments in leaves) having a negative impact on root growth generally. But wood would not have these pigments. To be fair some of the blueberry sites only referenced not using red maple leaves to increase organic content of soil. Red maples are higher in these pigments but it seems a stretch as they break down mighty fast.

Anybody else know anything?

I think I found answer in another question related to mulching. Blueberry root system live in symbiosis with certain fungus.

Here is quote:

Abgeschickt von Victor Tanneur am 09 April, 2001 um 12:09:28

I have heard many times that beech compost has a positive effect against fungus proliferation in the soil. (I have heard the same thing also about Canabis sativa compost.) Does anybody know more about the fungicide effect of beech compost? Is there any literature on this subject? If this method really works, it would be an easy way to avoid using too much pesticides (especially with young seedlings, which are so sensitive to fungus infection). Thank you very much in advance for your answer.
Victor

Sorry for being late to the party on this matter.

As referenced above by windfall rob there is the Penn State study on the Cornell U sight. It does state no red maple or beech.
http://www.fruit.cornell.edu/berry/ipm/ipmpdfs/bbmulch.pdf

I just spoke to Norse Farm in western Mass they said NO walnut or cedar.

An better answer would be nice.

ron

harvestman, are you thinking it is like the pine straw mulch?
Pine straw is on the low pH scale, but is neutral when it breaks down to compost.

ph is an exponential function.. to change it organically.. you would need about 40 thousand feet of it.. for about 200 years.. to have a minimal impact in the exponential reality of it all ...

i see the issue as what is a 'shaving' .. and whether or not it creates an impervious mat of rotting wood which restricts the flow of water ... and steals nitrogen in the process of the rotting ...

but i aint no fruit nut.. and you peeps sure do things differently ...

its just that you all seem to skip right by the fact that he doesnt actually tell us what the product is ...

in fact ... why is he not composting it first.. and if he is using it as a mulch .. it isnt going to change ph .. etc ....

ken

Here is a link that might be useful: it seems to vary widely

ken you missed the point, no one is tiring to change pH.
The OP is using wood shaving from a wood working shop(though the shop) as MULCH.
What is it he did not tell us?
Shaving like cheese or chocolate shaving, a thin piece of wood, not saw dust or chips.
My reply was to harvestman saying that it would not change pH.
I agree with him.