Black Magic Elephant Ears Near Death

Hello,
I live in Fort Lauderdale, FL. I purchased 2 Black Magic Elephant Ears from Spring Hill Nursery about 2 weeks ago. I received them via the mail in 2" pots with 2-3 leaves on each. I then potted them in 3 feet by feet 41/2 feet deep pots with miracle grow potting soil. Now the leaves are turning brown and curling around the edges. I have them in a sunny place and I keep the soil moist. What am I doing wrong? Please Help.

 

Maybe there are mineral salts burning the edges of the leaves. Look for salt deposits on the leaves. Multiple other things can cause leaf burn, if you can show a representative leaf to a volunteer at a Master Gardener clinic or a trained employee at a trusted independent garden center you might want to try that.