Opuntias are the easiest cactus to root IMO. They will root just about in any soil, but new soil would be better since you're not going to want to fiddle much with them and glochids can be nasty. You will want at least a few nutrients in the soil.

My family for generations has always just thrown the pads wherever they wanted the plant to grow and within a few weeks, if the soil has any moisture at all, it will root. You really don't even have to plant them upright as they tend to do that themselves over time. You would only have to moisten the soil a little but there would need to have at least a small amount of moisture, even a spritz from a spray bottle would be enough. Then let them do their thing, within a couple weeks you'll have roots, and a couple months it should be safe to lightly water without fear of rot.

Okay, I will spray it a little bit, then.

Thank you very much for the advice!

=]

I find that it is good to let your pad form a callous before you put it in your soil. Some people say 10-15 days. depends on the species. Then put it in your soil. Some say don't water till you feel some resistance, others say, to water it. I have done it both ways. If it is a beaver tail cactus, DON"T water it. some prickley pear are more H2O allergic than others.

I say Don't water any succulent start for a couple of weeks, even months in the winter. Succulents can take care of themselves while they make roots to search of water. Too much moisture while the plant can not absorb it will mean wet feet. In these conditions, fungus will infect the plant and cause a rot meltdown.

Watering early is just not necessary unless you are trying to root something very very small. A large opuntia pad has plenty of reserves to survive for months without roots and water.

I tug on all of my starts after a while. Gently. It is usually pretty obvious when there are roots holding the plant down. I recently rooted a large beheaded Echeveria 'black prince'. It literally pulled itself down into the pot as it made roots.