That is used for planting flower bulbs and you may find it hard to get the plug out intact in order to replace it with no sign of digging. When plugging is necessary I always dig in a cone shape so the plug comes out and goes back easily. I have dug plugs all over one of the nicest yards in town to get to deep old coins and the owners don't mind a bit since they can't tell where I've been.
Giterdone.
I thought of using a bulb planter before.Never done it but looked like it would work might just throw one in just in case butI'll use my plastic trowel for now.
they would appear to work but in reality they are not designed to hold up to the presure you have exert to dig a hole with one
of these things, on hard ground the sides can buckle and not give you the clean hole your trying to dig. stick with a metal trowel.