Preparing the Cutting
Put on gloves, safety goggles and a dust mask to protect your skin, eyes and lungs. Pick up the cutting and dust the broken end with powdered sulfur or other fungicide. If it's a large piece, you can cut it into smaller pieces at the nodes. Set the cutting aside in a cool, dry location for two to three weeks until the broken end has dried and scabbed over. Many gardeners dip the cutting in rooting compound before planting it.
The Potting Mix
The potting medium should be a light mixture that drains well. The University of Arizona Cooperative Extension recommends a mix of equal parts perlite and well-decomposed compost or peat moss. Alternatively, mix a commercial cactus potting mix with an equal amount of perlite to provide a suitable medium for the cuttings. Add water to moisten the potting medium and mix it thoroughly before placing it into individual pots or a seed-starting tray.
Rooting a Desert Cactus
Large desert cacti, such as prickly pear (Opuntia spp.), hardy in U.S. Department of Agriculture plant hardiness zones 3b through 11, may be rooted in large pots or outdoors. Smaller desert species are generally rooted in flower pots.
Dig a small hole in the potting medium and bury one-third to one-half of the pad or stem, bottom end down, in the mix. Place in a warm location in bright, filtered light. Don't water the plant until it begins to develop roots.
Rooting a Tropical Cactus
The tropical holiday cacti -- known as Thanksgiving cactus (Schlumbergera truncata) and Christmas cactus (Schlumbergera bridgesii), hardy in USDA zones 10 through 12, and Easter cactus (Rhipsalidopsis gaertneri), hardy in USDA zones 9a through 10 -- are native to Brazil.
Plant cuttings in the same moist potting mix as described for desert cacti. Cover the pot with plastic to keep the humidity high and water lightly when the soil is dry. Remove the bag when the cutting begins producing new sections, usually in three to eight weeks.
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