Do they not really affect the ph much until they are actually composted, meaning you cant tell they are pine needles anymore?

No they don't. Most composted material will end up in the neutral pH 7.0 range +/- a couple of tenths.

Dave

Ok, so if its a mix of composted needles and still intact needles im probably good then?

As long as it's a mulch (on top of soil) and not buried in (soil amendment),you will be fine ;-)

As far as the mulch is concerned you are. But I don't have any way to know what your soil pH is or was to begin with. But keep in mind that mulch as mulch doesn't really affect your soil pH, only tilled in matter will.

So if your soil was say a 6.0 to begin with and you till all the mulch in this fall it will likely raise your soil pH a couple of tenths. If your soil was an 8.0 then it will lower it a couple of tenths. But only after it is tilled in and then only temporarily. Once all the organic matter you tilled in has decomposed your soil will return to its natural pH. That is one reason why soil amending is an ongoing process.

Dave

Thanks everyone! I plan to use pine needles this yr. Last yr I didn't cuz I read somewhere else that you were not supposed to, too acidic. Now I find out that its ok to use them as mulch...yay! And composting is ok too.
Dave, thanks for all your info...very helpful!

I use pine needles as mulch - it's a great alternative to straw because I don't have to pay for it. They're easy to handle and one tree creates such an abundance of needles.

In my experience there will be a period when the pine straw is broken down and resembling soil but in fact too acid to support anything but the most acid-loving weeds, such as sheep sorrel. Over time where there was a pile of pine straw I would get only sheep sorrel, then grass again a few (maybe 3) years later. If you have heavier soil, dock would be a dominant acid-loving weed.

So it is a mulch lasting longer than its physical state would indicate, but you may have trouble germinating beets or spinach in there next year. Similar to wood chips, another long lasting mulch, but more extreme.

Solution: add wood ash or lime when fairly broken down, and rake (to mix) thoroughly, but only if you have to direct seed. If you plant seedlings through it, specially those that are somewhat acid-tolerant, as many summer veggies are, enjoy the mulch for one or two extra years. When, say, dandelions start appearing, it is time to replenish. You will know the thing is well done when clover (a neutral-loving weed) starts appearing.

There is some good information regarding the acidity issue (or lack thereof) here: http://www.pinestrawinfo.com/PineStrawMulchAcidity-SeparatingFactFromFictionThroughAnalyticalTesting.pdf

Here is a link that might be useful: Pine Straw Info website

Thank you all so much for your anwsers. It will be a mulch for now and get incorprated in at the end of the season with a broadfork because I am trying to get away from tilling. I am going to get a ph tester to make sure. I am glad I can use it as I have about 50 pines surrounding my property and the underneath of them needed cleaned out anyways. Most of it is already composted down but there are some needles too. Again thank you! I also have a wood burner so we are never short on ash to put on there to even it out later on!