AMES, Iowa – When houseplants get too large or more plants are desired, many can be vegetatively propagated. Vegetative propagation is growing new plants from vegetative parts, like leaves and stems. Propagating houseplants doesn't have to be intimidating, and species easily propagate at home utilizing techniques such as stem and leaf cuttings. In this article, Iowa State University Extension and Outreach horticulturists offer tips to propagate your favorite houseplants.
How do I propagate pothos, English ivy, or heartleaf philodendron?
Many houseplants, including pothos (Epipremnum aureum), English ivy (Hedera helix) and heartleaf philodendron (Philodendron hederaceum), are best propagated utilizing stem cuttings. Stem cuttings are produced using the tip or section of a stem with leaves and buds on it to produce a new plant. New roots form from buds on the lower portion of the stem.
To take stem cuttings, cut stems 3 to 6 inches long with at least two nodes (nodes are the places on the stem where buds or leaves form). Remove lower leaves and any flowers or fruit (if present). While not always necessary, treating the cut end with rooting hormone can help stem segments root faster. Stick the cutting into pre-moistened media (perlite, coarse sand or vermiculite) with at least one node and no leaves buried in the media. Firm the rooting media around each cutting to keep it upright.
After all the cuttings have been inserted, water the rooting media well and place the cuttings in bright, indirect light and high humidity. A plastic dome or bag is a good way to raise humidity. Periodically water the perlite over the next several weeks to keep the rooting material moist. Most houseplant stem cuttings will form roots in three to six weeks. When the roots are 1 inch or longer, plant the cuttings in a well-drained potting mix.
How can I propagate an African violet?
African violets (Saintpaulia ionantha) are propagated by leaf cuttings. Select a firm, healthy leaf and cut it off with a sharp knife. Leave 1 to 1½ inches of the leaf stem (petiole) attached to the leaf blade. Fill a pot with coarse sand, vermiculite, or a 50:50 mix of perlite and sphagnum peat moss. Moisten the rooting medium and insert the petiole of each leaf cutting into the rooting medium at a 45-degree angle. Firm the rooting medium around the petiole of each leaf cutting. After all the cuttings are inserted, water the rooting medium and allow it to drain for a few minutes.
Next, cover the cuttings with a clear plastic bag. Secure the plastic bag to the pot with tape or a rubber band. The enclosed environment drastically reduces the loss of water from the leaf cuttings and prevents them from wilting and dying before they have a chance to root. Set the pot in a brightly lit location. Roots usually form in three to four weeks. The leaves of new plants usually appear in six to eight weeks. Several plants usually form at the base of each petiole. Separate the plants by carefully pulling or cutting them apart. Pot up plants individually into containers using a well-drained potting mix.
How can I propagate the snake plant or mother-in-law’s tongue?
The snake plant or mother-in-law’s tongue (Dracaena trifasciata, aka Sansevieria trifasciata) can be propagated by leaf section cuttings. Remove a leaf and cut it into 3-to-4-inch-tall sections. For each section, the area closest to the base of the parent plant is the bottom and the farthest away is the top. 
Cut the top of your cutting at an angle or a notch in the top to help you remember which end is up, as leaf sections will not root upside down. Dip the bottom end of each section in a rooting hormone and then insert it one to two inches deep into a moistened rooting medium (perlite, coarse sand, or vermiculite). Keep the rooting medium moist with periodic watering. New roots form in three to five weeks and shoots should appear in about two months.
Can I root houseplants in a glass of water?
Many stem and leaf cuttings easily root in a glass of water. While many types of houseplants will readily root in water, the roots that form are more coarse in texture and not as well adapted to growing in regular potting soil. This means that once cuttings rooted in water are planted in potting soil, they will often show signs of stress, such as wilting, leaf drop, browning of the leaves or tip die-back. Providing good consistent care will help the small propagules recover after planting.
If water is used, change the water frequently (one to two times each week) and never allow the water level to drop and expose the developing roots to air. Transplant cuttings into potting soil when the roots reach about 1 inch in length.
Shareable photos: 1. Removing a stem piece for stem cutting. 2. Stem cutting beginning to root.
