Never on transplant. And I myself don't use epsoms(for magnesium) unless my plants are exhibiting signs of needing it. Usually this would be with a soil-less medium where i didn't add lime(or the potting mix didn't have any added) Or my ferts don't deliver it.

So, for me, in grounds don't get any. And my containers plants do since i use a 5-1-1 mix with no lime, but gypsum for my Calcium. And since I use Miracle Gro AP(no Mg or Ca), i use epsoms added to my weekly ferts at a rate of 1/2 tsp/gal to deliver my Mg.

Kevin

Thanks Kevin. I noticed that the soils here are a bit light on magnesium, but nothing severe. I'll add it from time to time as a supplement and hold on adding it during the transplant.

I sprinkle Epson Salt sparingly early spring just before planting. Then a lot of decent fertilizers (sold for peppers and tomatoes) already has magnesium in it.
This past year I also used it as foliar spray couple of times ( one TBS per gallon).

I would never add any kind of salts directly in the planting hole. Dilute it in water first.

Right. We're talking a tablespoon per gallon. It's WAY too easy to overdose adding it directly to the hole.

Dennis

I always add a tablespoon to the planting hole for tomatoes and peppers in the ground. Never had a burn or a problem yet. Cuts down on BER. Also use it as a side dressing. Just mix it in with the soil well before sticking the plant in...

I usually do not add anything to the planting whole, other than some compost or 5-1-1 mix to fluff it up. I either top dress or add to watering can. I figure everything will go down eventually, with a filtered form anyway. So everybody has a different method, I guess. I do foliar feed early on when the soil is cool and the root system might not be able to uptake. So that is just a short cut.