Um, what kind of place are you looking. You probably won't find it at big box stores. Generally, you'll find it either at larger, better independent nurseries and garden centers or at feed or farm supply stores. If you are looking to acidify your soil, you might find aluminum sulfate or powdered sulfur at some of the big box stores.

There probably isn't a national brand name -- most of these types of fertilizers seem to be made by regional or local manufacturers. Generally pretty much in generic bags with just the product information, pretty much the same way a lot of animal feed is locally produced by small manufacturers.

Isoh,

Agree with dennis. You're likely to find it at farm supply stores. Our local brand is APF, found at Rural King, and is $11.99 for a 51 pound bag. Aluminum sulfate can be found almost anywhere--but don't use it for blueberries. When I first started raising blueberries twenty some years ago, I'm convinced I kept killing them with aluminum sulfate.

I would not use Aluminum sulfate, that sounds rather toxic. But ammonium sulfate should not harm the blueberries unless you don't dilute it. It's not something you will find in any average nurseries, you can only buy it wholesale/via farm suppliers and you have to demonstrate you are a farmer. I think it's an issue of safety.

My local Home Depot carries the Shultz Super 21-0-0 Amonium Sulfate in the Lawn department. It is not easy to find, so poke around the lawn department where they have seeds and turf builder kind of stuff, but it is there. My local Orachrd Supply Hardware also has it. It is cheaper than any other fertilizer I have bought so far.

Here is a link that might be useful: Shultz Amm Sulfate at Home Depot

Axel: don't know about your area but it is easy to get here at the local elevator. Some commercial spray rig operations use it mixed with Glyphos for quicker burn down. You may be thinking of ammonium nitrate re: safety concerns, not ammonium sulfate.

DenninmiÂs recommendation of Aluminum sulfate was fine axel_sc. Aluminum is toxic to some plants but not blueberries; they do not uptake it as food... so it does not enter the plant. And as far as humans go, they use it in the manufacture of pickles and the purification of water.

Just to add, iron sulfate also helps lower PH.
http://www.amazon.com/Bonide-920-Iron-Sulfate/dp/B0015HXLAI

ammonium sulfate on line
http://www.ruralking.com/ammonium-sulfate-fertilizer.html?cvsfa=1908&cvsfe=2&cvsfhu=303137333230303136

I've always used iron sulfate, never aluminum sulfate. I had no idea this was used and is considered safe. Is it safe if other plants absorb it?

Aluminum sulfate is unusually powerful pound-for-pound in lowering pH, but for a home orchard why not just use more sulfur, which is almost entirely without unwanted side effects (though it does smell a bit). Aluminum is toxic to most plants and is most available to them at very low (and also I believe very high) pH's.

Ammonium sulfate is worthless in any improvised explosive and is not regulated as such. Ammonium nitrate, and in this state urea, are restricted for that reason, even though urea is not that big of a deal.

Bananas: what sort of hoops does one have to jump through to be able to use urea in your state, what state is it? I can walk 3 blocks to the elevator and fill up a 5 gallon pale for nearly nothing and walk home, no I.D. or background check required. Good God this is getting ridiculous. It was bad enough when the federal government could no longer trust me to use ammonium nitrate for my garden in the Spring, is urea next? Guess I'll have to switch to URAN and inject it and buy a RPZ that costs $500 to prevent back flow into the water system of course.

SC. It's a goofy rule and quite by coincidence I know (and like) the people at the Clemson department who made the rule and have told them it's goofy. Sure, you can make an explosive out of it but so can you, for example, with the perfectly safe glycerin on the drugstore shelf or for that matter your cotton T-shirt. It's the OTHER dangerous stuff you need to use that is effectively and correctly controlled (highly concentrated nitric acid).

Like ammonium nitrate, urea is probably still available to the big commercial farmer, though I am not sure.

The one thing I remember from living in FL and using amm. nitr. is that it is hydrophylic, leave an opened bag laying around in 100% humidity long enough and it will turn to a bag of soup. I think it may be more expensive on a lb. of N/ton basis than urea also. Just a wild guess but, it may be more popular in the dry climate regions where it is easier to store.

In southern California any big box store sells ammonium sulfate, usually in 20 pound bags. It is probably one of the easiest high nitrogen fertilizers to find, and usually pretty cheap. Urea has more nitrogen, but is harder to find places that sell it.

I found it at home depot, however one of the pet stores in the area also had a product called "pH down" which was just concentrated sulfuric acid.. Mix it into 2-5 gallons of water and use that as your starter solution to make a watering solution with a pH that you need. I may not need it though.. the stuff from home depot did a good job lowering the pH of the potting soil I used from 7 to 5 for the blueberries. The leaves are turning back to green now. :)

I'm guessing the availability of amm. sul. is related to the common pH of soil in the region fertilizers are sold. CA's interior valleys tend to have extremely alkaline soils and the west tends to run base in general so it would be widely useful there to lower pH.

Yep! It's easy to find in Southern California. We used to put it on our lawn and it would green up instantly! I am now going to get some for my blueberries. Good suggestions in this thread.
Suzi