Hi Critter, personally I do not like miracle gro cactus mix just because they keep adding those fertilizer additives. Plus as mentioned by Lynn their mix seems to have more peat moss. Their mix seems more suitable to other types of container plants/tropical plants, or since they intend it also for citrus, yes the citrus plants will enjoy that.
Besides during winter time, these succulents slow down in growth, so they have no need for fertilizers. However, if you have no other choice but to use their mix, do add some more perlite or pumice to their mix to really make it very well draining.
Sempervivums and some sedums struggle on my side due to our extremely long dry heat months, but they are happiest during our cold season. But I have learned to make their media much grittier, really adding more rocky media to it. They hate soaking wet media, and unfortunately our winter here is at times rainy. I know growers that have snow conditions just leave them outdoors and have better chances surviving being insulated by snow, but you have to make their media very gritty and coarse to allow quick drainage. Sempervivums and sedums are alpine succulents so they can bear the cold.
