I am going to plant spring flowering bulbs in the fall. I would like to know if I need to add the depth of mulch to planting. For example, if a bulb needs to be planted 4" down. Do I bury the bulb 4" down into the ground, and then add the thickness of mulch to it, and it does not matter hoe think the mulch is? Or I have to add the depth of mulch to the ground depth as a total, such as 2" ground and 2" mulch?????

Thanks