Wow! that's a really acidic garden. For the sake of the microbial community small changes would seem best, but that seems really low. What are you growing, or wanting to grow there?

Unfortunately, this is my vegetable garden. There is a bit of peat moss in there, but I think most of the acidity comes from years of manure in the soil. Thank goodness I had it tested and know how acidic it is now!

Spread it this fall, and dig or till it in.

Manures tend to be alkaline, so adding that shold help raise your soils pH. Your soil needs that much lime and it needs it all at once, now, in the fall so that maybe by next spring the soils pH will be near what you want to to be. It takes lime a long time to begin to influence your soils chemistry, even if you put down hydrated lime, so putting some down now and more next spring will not be at all helpful for growing much of anything.

Thanks everyone! Okay, I'll dump it all on now and mix it in. Keeping my fingers crossed that it works well over the winter!

You may want to do some reading during the winter.

Here is a link that might be useful: Handbook of Soil Conditioners