Thanks guys. The potting mix is MG for cactus/citrus mix + perlite + vermiculite + some of earthworm castings. I should add some sand but didn't have it when corms arrived. So I agree with Keith it is not loose enough. I didn't water them since they were planted so the soil is moist not too wet. I cut the dead parts this morning but I am not sure if this way is OK.
Should I keep them in shade or move to partial sun (morning sun)? And, should I add some sand to the soil or leave as it is?