How Should I Propagate New Indoor Plants?

There are many ways of starting new plants, such as by cuttings or slips, divisions, air layering, and, of course, seeds. The best time for taking cuttings is when the plant shows strong growth. Snip off a three- to five-inch piece from the tip of the plant. Then remove the bottom two or three leaves from the cutting, and place it in the rooting medium.
Cuttings of philodendrons, begonias, coleuses and many other soft-stemmed plants root easily in water alone. In most cases, however, plants root better in a plant medium such as peat moss or sand, or a mixture of both. Perlite and vermiculite are also excellent rooting mediums as they hold water well and are disease-free if a fresh batch is used each time.
Cuttings from woody-stemmed plants often need a little encouragement to root, and this may be supplied by means of a rooting hormone. Dip your cutting in water, then in the hormone powder, and tap the cutting to remove any excess powder. Next, poke a hole in your rooting medium to avoid scraping off the powder when placing the cutting in the soil. Finally, place the pot in a bright area, but not in the direct sun. To speed up the rooting you might try covering the cutting, pot and all, with plastic material. The idea is to hold humidity in, forming greenhouse conditions as nearly as possible.
Leaf cuttings of the wax begonia and gloxinia can be made in the following way: Make slits or cuts in the veins of the leaf in three or four places. Then lay the leaf on moist sand, with the cut side down. Next, peg the leaf down with toothpicks or small stones, and insert the stem of the leaf in the sand. New plants should arise from the cut areas.