Epsom salt will work, but usually just in the short term. Epsom salt is very water soluble and will each out of the soil fairly quickly. Dolomite Lime is a good source, it is made of calcium and magnesium and is more stable for the long term. A great thing is to use compost with a high percentage of tree leaves in it. Trees have deep roots that can go down into the bedrock, depending on the tree and get many of the minerals they need that way. Dolomite Lime can usually be bought at home depot or lowes, or if not available, you can buy over the net but the shipping costs are going to be outrageous. I would use some dolomite lime now to start correcting the issue, and add compost this fall and again next spring.

Magnesium sulfate contains 20.2% Mg and 26.6% S. By weight it would be 20.2 lbs. Mg. and 26.6 lbs. S in a 100 lbs. bag of Epsom salts. So, using a little middle school math:

20.2 --- 100
1.5 --- x

x = 150 / 20.2 = 7.5

That is, for 1.5 lbs. of magnesium, you will have to use 7.5 lbs of Epsom salts.

Now the question is, "What is the area that the 7.5 lbs. needs to be spread?" Does the report say if it's per acre or per 1,000 sq. feet?

Any drug store sells Epsom salts. Why do you have to go online? The shipping will cost more than the Epsom salts. Costco sells big bags of Epsom salts.

The pH of my soil is just where I want it, which is why I was not told to add any lime. But will the salts in the epsom salts mess with the pH like I think they will?

The recommendation was for 1-2 lbs per 1000 sq feet.

I do use tree leaves (oak, maple, and poplar) in the fall.

Thanks for the math, I wasn't sure of the Mg concentration in epsom salts.

Epsom salt is very water soluble and will each out of the soil fairly quickly.

That makes no sense at all. Sure, Epsom salts dissolve in water, but that doesn't mean that Magnesium will leach out of the soil. If the soil has enough organic material, the magnesium will remain.

In re: dolomite lime vs. Epsom salts; the lime helps raise pH and the Epsom salts will help lower pH.

Mg .. 1 .... 24.310 ....... 24.310 ... 20.196%
S .... 1 .... 32.065 ....... 32.065 ... 26.638%
O .... 4 .... 15.999 ....... 63.996 ... 53.166%
MgSO4 molar mass .. 120.371 .. 100.000%

Formating this is harder than the math

If you really stop and think about it 1 to 2 pounds per 1,000 square feet is only a very light dusting, not really enough to be concerend about. While the material that is the carrier may make it look like a lot that 1 to 2 pounds of actual Magnesium does not amount to much at all. I would not be concerned about it especially if your soils pH is on the 6.2 to 6.8 range.

If you check the garden section at big box stores, you may find epsom salts there for much less than in the pharmacy department. I think it's the difference between fertilizer grade (or maybe agricultural grade) and cosmetic grade.