The best time to propagate houseplants is while the plant is actively growing. The most common methods are stem cuttings, leaf cuttings, division, layering and airlayering.
STEM CUTTINGS:
These work effectively on soft-stemmed plants such as Coleus, Syngonium, Hoya, Dieffenbachia and Philodendron. Use a clean, sharp knife or snip. Cut a 3- to 4-inch piece of stem from the tip of the parent plant. Make the cut below any node on the stem.
Take a clean container and add a good potting media up to about an inch below the top of the container. Take off the lower leaves and leave at least two nodes bare for insertion into the planting media. Dip the stem into a rooting powder and plant directly into the media. Water thoroughly after planting.
To increase the chance of success, enclose the pot in a clear plastic bag, making a miniature greenhouse for the cutting which increases the humidity. Place the plant in a warm, shady area. The cutting will signal root development by showing signs of growth. Then remove the plastic bag and continue to keep the soil moist to encourage a good root system. Gradually bring it into more light. The variety of the plant will determine how much light it needs.
Rooting in water:
Not all plants root in water. Some that do root well in water are Creeping Charlie, Pothos and some Philodendrons. Within ten days the root will begin to appear. Plant the cuttings in small pots when a good-sized root system develops in a good potting media. Cuttings may suffer or go into shock when moved from the water into the soil. Keep water clean and fresh, changing every few days or add horticultural charcoal.
LEAF CUTTINGS:
The leaf cutting method of propagation works well with African violets and some succulents. Using a sharp knife or scissors, cut an entire leaf with stem from the parent plant. Cut the stem to about 1-½ inches in length, making a diagonal cut. Allow the cut to callus for an hour. Insert the leaf in water after adding a little horticultural charcoal. You can also place the cutting directly into the potted media after dipping the stem end into rooting powder before planting.
Cover the container with aluminum foil or waxed paper to make the leaf stand up with the stem dangling in water. Secure it with a rubber band. Make a small hole in the top and lower the leaf through the hole. This will allow the stem to dangle freely in the water without wetting the leaf.
After roots appear and are about ½ inch long, you are ready to pot the rooted leaf. Use a small (2 inch) container to pot the newly rooted leaf. Repot into a larger container after the plant has several leaves. In potting media such as peat and perlite or vermiculite, use a ½ inch peat and ½ inch perlite or vermiculite. If placed in this material, insert the leaf at a slight angle and lightly place the mixture around the leaf. Succulents will readily root when placed in part soil, part sand, part perlite or vermiculite mixture.
DIVISION:
This method works with plants that have multiple crowns on those growing from more than one main stem. This includes the Aspidistra or Cast Iron Plant, Spider Plant or Spathiphyllum. Carefully remove the plant from the pot and gently pull the clump into desired sections. Use a sharp knife to cut through the root ball for plants with particularly thick and tough roots. Try not to damage the root system. It is best to pull the plant apart as much as possible before using a knife to cut the roots. Pot the new sections after you have divided the plants.
LAYERING:
Vining plants can be propagated by winding the stem around so that it makes contact with the soil. Hold the vine to the soil with a hairpin or a paper clip cut in half or a small rock. New roots will form at the nodes. Cut the stem off after the roots have formed. Remove the new plants and pot separately.
AIRLAYERING:
For Dracaena, Ficus and other nonvining plants airlayering is accomplished by removing one inch of the bark around the stem, dusting with rooting powder. Then cover above and below the cut area with moist sphagnum moss and wrap with foil or plastic. Depending on the plant and time of year, it will take a few weeks to several months for roots to form. Make sure the sphagnum does not dry out. Once roots form, cut the rooted section off and pot.
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