You don't want to plant it deeper than 8 inches, from the soil surface to the bottom of the bulb, unless you have good drainage below that - a rarity unless you are in sand. But putting lots of mulch over it AFTER the ground has become its coldest will certainly help slow spring growth by keeping the ground cold. This means putting mulch on in mid January. Or, if you can transplant it to a place where it gets shade in the spring, like a north slope, or the north side of evergreens.
