I'm sure these augers make bulb planting easier (given the right soil conditions) but I've used the larger one for something completely different. I installed a 50 foot section of palisade along the border of my property to add some privacy where a few trees used to grow. Although the trees were felled and the stumps sharpened, the roots were everywhere. Trying to find places to dig post holes became a nightmare, and in some places I had to use 2" galvanized pipe to support the fence. That's where these drills come in. I attached them to my drill and continued. drill with a drill. I've hit the root a few times, but because they're so much smaller than a shovel and I only needed 3" holes, they were able to get in between the roots and find places a shovel would never fit. Based on the fact that I've encountered some hard stuff and they haven't broken, I suspect they will work in almost any ground except really rocky ground.