When I pot up, i sling some dirt in a pot, move the plant to the pot and dump in some dirt. I fill the pot 90% full no matter how deep vin the plant is lol. I've buried 1 to 1.5 inches without a problem. I had one photo period ( don't remember the strain, that died after transplant. It may have however, been root rot not stem rot. I'd say and helthy plant with no damage on the stem will take burying deeper with not problem. If you use soil, you top dress right?