These are sold by the hundreds in WalMart, Lowes, etc., in a variety of forms (Mr. Red Top, etc.). The green ones can grown on their own roots. Yale

Huh,isn't that funny? the label on the pot says gymno,moon cacti. But,I think your right-they are Euphorbs,not cacti. Thanks for offer Joe,but I have some tree amamaks on the property..this little one did fool me into thinking i had a rare Hylocereus sp. On the other hand, I think a graft of Euphorb cactids will be longer lasting than grafts between true cacti..we will see...

I think your grafted plants have been pampered in a 'cactus factory' (not nursery!) in colder climate before you bought them. Therefore they cannot cope with your climate. And in general plants/scions lacking of chlorophyl are very susceptible to heat and too much light. The monstrous cereus would do much better on its own roots. I would cut off the understock, apply some rooting hormone to the cut if you have and keep it vertically in dry soil, coarse sand or pumice IN your home for 2-3 weeks, then keep it slightly moist or spray it and wait till it is starting to grow, then slowly acclimate it to its future stand. Jordi

I looked for some pics of coral cacti. Technically not cacti but looks like the scion has some green in it so it might be able to survive without a different rootstock. However, if it can survive well without a different rootstock then I doubt the nurseries producing it would bother grafting it. Rather than cutting off the whole crested scion you might watch for a small outgrowth of it, cut off the outgrowth, and try rooting it. That way you'd still have the original plant if the cutting fails to grow on its own. Most grafted moon cacti have no chlorophyll and won't survive on their own. However, I've seen some scions that have a mix of colors, including the normal green, and some that are very dark purple. The dark purple ones might have chlorophyll. The ones that have a mix of colors including regular green might be able to photosynthesize enough to support the rest of the plant. The brighter solid color scions have no chlorophyll and can't photosynthesize. As far as I know no amount of fertilizer or supplement will make up for the lack of photosynthesis. Without a photosynthetic rootstock the ungrafted nonphotosynthetic cactus will die. Often the scions will produce pups. You can try cutting them off and rooting them so you'll always have the original grafted plant. I expect you'll find the cuttings don't grow and eventually die.