It'd probably be okay or even better to let it age and compost a bit. Brady

Decomposed or not, it is beneficial as a mulch.. I could see problems if you till in green or dry matter into your soil, which would pull carbon/nitogen out of your soil to decompose it... If you leave the chips on top as a mulch nitrogen from the air can help it decompose, flip side for green matter.. I cannot see how pine mulch can hurt as a mulch.

The acidifying affect of pine mulch- even the needles is over rated- probably based on the fact that hardwoods contain more calcium as well as many other minerals by weight than conifers. Anyway, bags of lime are cheap and pH of most soils needs to be managed one way or the other.

Fresh pine mulch should cause no problem unless your soil has poor drainage and feeder roots are primarily right at the surface. There is a possibility that in these conditions it might result in N deficiency but this rarely happens and can be countered with N application.

I'd use it without fear.

I'd use it...I've used ground up Christmas trees (that had needles in them)...they worked fine... I use about anything for mulch...

" I use about anything for mulch..."

Me too. I haven't recycled any paper products for years. I throw them in a barrel and when the barrel is full I dump it next to a tree and cover it with wood chips. I do this w/ old phone books, catalogs, anything paper.

When I've been short on mulch, I've used old ragged cotton clothing to cover the ground. It keeps the weeds down for a full season.

For wood chips, I use whatever the tree services give me (pine, walnut, etc.) and never seen any difference in the trees from using one mulch or another.

I've rarely had problems with any mulch materials, but here are a few cases where I have:

Once I heavily mulched some tomatoes with grass clippings that I expect contained some broad leaf yard herbicide. The tomatoes showed some herbicide stress. Tomatoes have a much higher sensitivity to herbicide than most trees. My trees have never shown herbicide stress from grass clippings.

Grass clippings will get soggy and can greatly reduce oxygen transfer in the soil, which can be a problem for soils prone to water-logging.

Another time I mulched a young peach tree with a bunch of shredded paper (bags and bags). The foliage of the tree didn't look right afterward. Shredded paper has a lot more surface area than unshredded and it may have been the carbon leached down in the soil from the sheer amount of shredded paper and caused some N deficiency. I don't know for sure, but it took a couple years before the tree straightened out (I haven't seen this detrimental effect from one or two barrels of unshredded paper under a tree.)

One fall I cut up a bunch of walnut in the garden area. There was about 4" of walnut bark and sawdust where I planted my corn the next spring. The corn didn't do very well, probably because of lack of N (corn is a fairly shallow rooted plant and so the roots may have been exposed to the N deficient sawdust) and possibly juglone was playing a role. The next year the corn did fine though.

Olpea, I believe your method of using paper also creates a water reservoir even beyond what's provided by rotting chips. I used to bury soggy newspaper in my nursery for the purpose and a mass of feeder roots invariably surrounded and penetrated the paper when I dug them up. We haven't had drought last few years so I've stopped bothering.

"Olpea, I believe your method of using paper also creates a water reservoir even beyond what's provided by rotting chips."

Probably does.

I use it mainly because it takes quite a while to break down and so provides a weed barrier in addition to the wood chips. It probably also provides some organic matter.

I once read about some farmers tilling shredded newspaper in their soil to increase the organic content. I don't recall now, but I'm sure the article would have recommended adding more N to compensate.

Another question, then. What about walnut trees as mulch. Some folks say they won't use tree mulch from local tree service because it contains black walnut and that it has something in it that stunts growth of other trees and plants. Would that be true?

I use pine park to mulch my fruit trees had no problem. Just keep the mulch 1 1/2 to 2 inches away from the trunk.

"What about walnut trees as mulch."

I've mulched peach trees w/ solid black walnut mulch. Even had lots of walnuts mixed in. Never saw any difference in the performance of the trees vs. other wood mulch.

When you get mulch from tree services, you're likely to get anything. I get lots of different mulch and it all works. My least favorite is probably honey locust (which we have a lot of around here). The thorns are about 2" long and sharp as a needle. Sometimes their chippers don't chew up the thorns which can flatten rubber tires if you run over the mulch.

Maple wood chips have the slight disadvantage of a higher percentage of germination of their "helicopter" seeds. All wood mulches will germinate their seeds in them, but maple mulch seems to do it more than oak, walnut, etc.

The only other problem I've had with wood chips is that once I had a tree service that delivered several loads of wood chips with about 50% logs mixed in. It took quite a bit of effort to sort out the logs.

Occasionally you'll get some trash mixed in with the chips but that's generally not too bad unless you get truckloads of leaves in which there will probably be tons of trash mixed in (at least in my experience). Lawn crews vacuum up all the leaves and they vacuum all the trash up with it (i.e. aluminum cans, plastic bottles, plastic bags, etc.) Whatever people toss out of their cars ends up mixed in with the leaves.