pH is a exponential function ...

to have any significant change in the pH.. you would probably have too put about 100 feet of pine needles on the garden.. for about a hundred years ... to do so ....

unless your soil is so borderline one way or another.. that this little impact might change it ... which i doubt ...

incorporating raw wood into soil... can lead to other problems .. unrelated to pH.. if you dont compost it first ....

i dont understand when you say you MULCHED the tree ... do you mean you cut it down.. had it chipped and composted it all???

also.. you say as a covering.. just about anything can be used as a mulch.. a top covering ... to reduce heat... and retain moisture ... etc .... but being on top.. it usually has no real impact on the soil below.. unless it is left there so long.. that it completely decomposes.. and turns in humus and/or soil ...

ken

ps: raw wood utiliized all available nitrogen in decomposing ... so if you puttoo much raw wood in ... you might up with chlorotic.. yellow..plants ... as well as drainage problems .... etc ...

Sorry for the sketchy description! I had a tree service chip a couple of dead standing trees

( for 3-4 + years ), one of which came down in the storm, a couple of weeks ago in a 50 mile an hour gusty night! I didn't put in all that much basically a light covering on top & will add compost and mulched leaves and rake it out in the spring. thank you!

Pine mulch is pH 3.5-4, and if used in large quantities, it can result in acidic soil. That being said, most soil has natural buffering, so you're not going to end up with soil that acidic. Of course, it also depends on the pH of the soil you're putting it into. If your soil is already acidic, it will make it moreso.

If you are digging in uncomposted material, yes, the soil nitrogen will be compromised. But you won't have any such problem using it as mulch.

" If your soil is already acidic, it will make it moreso."

This is really a gardening myth :-) And one that tends to continue to be promulgated by various online sources despite all scientific evidence to the contrary. The amount you would need to apply to make even a small change in pH would be huge! And would need to be renewed constantly and stay in place for years to have even a small effect. Yes, the pine chips may be acidic. But the acid that may leach from them when applied as mulch is insignificant and will be restrict to only the soil surface. And the acidity dissipates with time so that once the chips start breaking down and decomposing, they are no longer acidic at all.

That's correct. When used as mulch, there will be little acidification. But if you dig a lot of the stuff in, uncomposted, there can be an effect on the pH. Fresh needles ARE pH 3.5. That's a fact. It WILL acidify. The myth is that pine can actually acidify the soil to dangerous levels. That won't happen.

The acids in pine are organic acids that will eventually biodegrade, so the effect is temporary anyway. And if the tree has been dead for some time, some of that biodegradation has probably already occurred.

I would think a fall mulch with this stuff would be great.

The pine chips will make a great mulch for the veg garden. Just don't dig it in to the soil and it will be fine. Of course, unlike leaves or straw, the pine will still be very much intact come spring and summer, so just push it aside to plant stuff. It will decompose in a couple of years.

I use woodchips in my potting soil with no ill effects. I also till in 4 inches at a time and then top that off with another 4 inches as mulch with nothing but good results for the trees planted in it. It does absorb a lot of water though before being damp enough for good growth. A good soaking before planting really helps if done in the Spring or early Summer.

I have put 4" of christmas tree chips on my flower beds for 15 years. Not composted or dug in. The PH has not changed from 7.2 in any year according to soil tests. What it did do is make it so I can put my arm up to my elbow in the ground. I have glacial till soil, so kind of sandy and small stones, and 4" of chips is gone in a year.