Epsom salts contain magnesium and sulfur that is good for leaf growth. Some folks use epsom salts for desert roses after pruning or add it to the soil to fertilize the plants. The trick is to not sprinkle it on the stem and leaves, because it will cause burning. Sprinkle your salt around the soil and give it a shower of water afterwards. When you see the salt disappears on the soil surface, you're good to go.