Cactus species are among the easiest plants to root at home, even for first-time gardeners. The process works any time of year, but cactus cuttings potted in late summer to early autumn root fastest and produce the healthiest plants. Despite the ease with which they root, cactus cuttings must be properly prepared beforehand and potted in sterile rooting material to keep them from withering and rotting before they take root. Once potted, most cactus cuttings root in four to six weeks and are ready for transplant one month later.
Root cactus cuttings in late summer or early autumn when nighttime temperatures are above 60 degrees Fahrenheit and daytime temperatures are between 75 and 85 F. Avoid rooting cactus cuttings in the full heat of summer since they dehydrate quickly, which slows rooting.
Sanitize the blade of a serrated knife with a cleaning solution made of 1 part bleach and 9 parts water. Rinse and wipe the blade clean. Allow the blade to air-dry before using it to harvest a cactus cutting.
Harvest a 3- to 5-inch-long cutting if rooting a columnar cactus, a whole pad if rooting a paddle-type cactus, or a small offshoot if rooting a barrel cactus. Sever the cutting at a 45-degree angle using the sterilized serrated knife.
Store the cutting in a cool, dry spot under very bright yet indirect sunlight for at least 10 to 15 days. Check the severed end of the cutting periodically for callousing, which is when the cut heals over and turns a dull whitish color. Pot the cutting once it callouses over.
Fill a 4- to 6-inch diameter pot with a mix of half perlite and half coir or peat. Press the mix to remove any air pockets. Dig a hole in the mix that is deep enough to accommodate the bottom one-third to one-half of the cutting.
Dust the calloused end of the cutting with commercial rooting talc. Apply it with a cotton ball or dip the end of the cutting directly into the powder and then tap it to remove the excess.
Insert the cactus cutting into the hole in the perlite and coir mixture. Fill in around the base. Firm it well to steady the cutting. Add more growing mixture to fill the pot completely, if needed.
Place the potted cutting outdoors where it will receive bright, filtered light and temperatures above 60 F. Provide protection from strong wind or salty spray, if rooting the cactus in a coastal area.
Water the cactus cutting five days after potting it. Drizzle water around the base of the cutting until the perlite and coir mixture feels damp 2 inches below the surface. Wait until the mixture is almost completely dry before adding more water.
Test for roots four weeks after potting the cactus cutting. Wear gardening gloves or use tongs to grasp the base of the cutting. Lift it gently and feel for resistance to the movement, which means that roots have formed.
Things You Will Need
Coir or peat