Like most succulents, you can propagate a cactus via stem cuttings, offsets, or division. Seeding, grafting, or direct planting are viable ways of propagating a cactus, but they are challenging for starters.
The best time to propagate cacti plants is late Spring or summer. Propagating your cactus using cuttings is the easiest as the roots grow much quicker during these seasons.
Tools and Materials:
- Heavy-duty gloves
- Potting mix
- A sharp knife/pair of shears
- Spray bottle/watering can
- Rooting powder (optional)
- Tongs or cactus pliers (optional)
Step 1: Take A Cutting
Cut a healthy cactus pad using a sterilized pair of pruning shears or a sharp knife. Use tongs or gloves to protect your hands from the cactus spines.
Ensure your cutting contains a part of the cactus stem and is at least a couple of inches long. Allow the cut end to callus over for a few days to a week to prevent rotting. The callusing period reduces the chances of bacteria or fungus getting into the cutting after it’s planted in the soil.
Step 2: Prepare the Planter
You may prepare your growing mix or buy from a gardening store. A suitable potting mix comprises one part potting soil with one part perlite and one part orchid bark.
Adding perlite or sand to the potting mix improves drainage. Since cacti are sensitive to overwatering, use a compact pot or container with sufficient drainage.
Step 3: Planting and the Growing Process
Put the callused end of the cactus pad into the potting soil while keeping it upright. Moisten the soil after planting to help it settle around the cutting. Place the container in a bright area where the cactus may get bright but filtered sunlight, or use grow lights.
To avoid root rot, keep the soil wet but not waterlogged and let it dry between waterings. With time, your cactus cutting or seeds will develop and establish themselves in their new container.
Step 4: How to Care for Your New Cactus
As the cactus continues to bud, increase the light it receives. Ensure it gets at least 6 hours of indirect light daily.
Most cacti are prone to drying out between waterings, so check the soil’s moisture level and use as little water as possible. Fertilize your cactus with a diluted, balanced cactus fertilizer during spring and summer (growing season) to encourage healthy development.
Watch out for pests or symptoms of disease, and take immediate action. As your cactus grows, repotting it into a larger container may be necessary.
Other Methods of Propagating a Cactus
Propagating from offsets/offshoots
Offsets, offshoots, or cactus pups are small, new growths connected to the parent plant. Propagating cacti from offsets is a vegetative form of propagation.
Vegetative propagation is when a parent cactus produces an offset without the transfer of seeds (asexual).
- Wear gloves to protect your hands and separate the offset from the parent plant. You could either use a clean, sharp knife or your hands.
- Allow the separated offset to air dry for one or two days. This period helps it develop a callus.
- Make a small hole in a smaller planting pot with suitable cactus soil and place the callused offset into the hole. Ensure you compress the surrounding soil after planting.
- Place the planted container in a location that receives bright but indirect sunlight. Remember to water the soil when it feels dry.
- As the branch matures, increase its sunlight intake, similar to a mature cactus.
You can’t propagate all cacti from offsets. Avoid dividing the offsets of the following cacti:
- Lobivia silvestrii
- miniature Rebutia cacti
- Echinocereus engelmannii
Propagating from Seeds
Cacti seeds are a great way to propagate rare cacti species that don’t produce pups. Note that the success rate is lower, and the growth time is longer.
- Start by picking cactus seeds from a mature cactus plant. You could also buy them from a reliable seller. The most suitable time for sowing cacti seeds is in early spring.
- Next, if you are not using a premade mixture, create your potting mixture. Fill a pot with gravel, charcoal, small gravel, coarse sand, compost, and rocks/gravel. Divide the surface of the compost to ensure the seeds have space.
- Press the cactus seeds into the soil’s top layer, but don’t bury them.
- Mist the soil to create a humid atmosphere and help the seeds take root. Also, consider covering the pots with plastic wrap to preserve moisture and warmth.
- Put the containers in a location that receives warm, bright, but indirect sunlight. Ensure you observe the soil’s wetness to ensure it doesn’t get too wet or dry.
When propagating a cactus from seeds, it’s worth noting that there are two types of cacti. The first produces seeds without cross-pollination. It comprises most Mammillaria, Cereus, and Echinocactus cacti. The other includes cacti that pollinate with their pollen.
Propagation of a cactus via grafting requires joining two different cactus species together. Grafting is best for joining a hardy rootstock and a desirable scion. Cactus grafting propagates non-photosynthesizing cacti species like moon cactus and variegated species.
It’s also effective in replacing rotting stems and aids in growing cacti that struggle with root development. These species include the astrophytum, rebutia, and Lophophora species.
- Start by choosing a clean and sterilized razor or sharp knife.
- Next, choose a healthy cactus plant and prepare a scion. Use your sharp instrument to cut off at least a one-inch stem (from the top).
- Then, proceed to prepare the rootstock. Behead a cactus within a few inches (7.5 cm) of the soil.
- Ensure you cut the rootstock and scion cactus in straight, diagonal lines to generate matching surfaces for grafting. You could also ensure perfect alignment by fastening the scion to the rootstock using rubber bands or grafting clamps.
- Allow the grafted cactus to recover and solidify for several weeks. During this period, ensure a warm, dry, and well-ventilated environment for its growth.