I've seen sulfur at a garden supply store here, but it wasn't a big box store. It also wasn't pelletized.

It's not easy to bring the pH down in a lawn. Spreading the sulfur on the surface isn't particularly effective, because too much goes into the atmosphere instead of converting into acid. If you can mix it in even a little bit, you'll have better results.

What about after core-aeration? That's when I was planning on applying it. Also, what form was it in at this garden supply store? What form does it usually come in? Thanks.

After core aeration would be better than just putting it on the surface, especially if you could water it well (or had rainfall) shortly after spreading it. I used it to try to lower the pH around a tree and used a bulb auger to make holes around the dripline of the tree. Since I was taking a more "concentrated" approach, I could drill a hole, pour a cup or two of sulfur and cover with dirt again.

The stuff I used was more like flakes than pellets and they sold it in bags labeled "soil sulfur".

Something else that you can try is adding organic matter. It has much less effect, but gradually tends to bring the pH closer to neutral and also has a buffering effect, so that even though the pH is high, the plants are better able to use the nutrients than without the organic matter. That approach takes years to have much effect and you need to keep adding organic matter on a regular basis. I mulch mow and also mulch mow tree leaves. And I spread used coffee grounds from Starbucks as often as I can.

I think the pH is still a little on the high side, but at least I no longer give directions by telling people it's the house with the big maple with bright yellow leaves. The bright yellow leaves were due to iron chlorosis (plenty of iron in the soil, but not available to the tree).

Martin Resources makes a 50 pound bag of a granular sulfur 90% that is much easier to spread than the flaky stuff like the Hi-Yield Brand. It's not dusty and has uniform granuals.

They make some other types too, but this is the one with uniform granuals and not dusty. I don't know what the others are like.

http://www.martinresources.com/disper_sul.php

It's called "soil sulfur" around here, and it's sold in garden centers and nurseries.

I will have to say that for the past 3 years, I have put down sulfur and after what seemingly was some progress in getting pH to lower, my latest soil test showed that my pH is as high as it was originally--7.8. I think there is a reason that none of my soil test interpretations came with recommendations to put down sulfur--it probably will not be effective or longlived.

Looking for this information... Very helpful. Still accurate? Thanks in advance for the help!