Cloning is a hot topic these days, but growers of African violets have been doing it for years. You and your child can, too. It's easy to propagate tiny plantlets with leaves and flowers exactly like the mother plant, and with the right light, temperature, and fertilizer, they'll grow into beautiful houseplants that bloom most of the year.
African violets (Saintpaulia ionantha) are the most popular houseplants in Canada. They were first discovered in West Africa in 1892 by Baron Von St. Paul of Germany, and by the late 1920s breeders had developed a few hybrids. Now flowers come in a variety of colours-purple, pink, white,blue, burgundy and bicolours-on plants with plain or scalloped, green or variegated leaves. Since not many types grow true from seed, the best way to get more plants is to root a leaf cutting. Roots develop from the petiole, the area where the stem meets the base of the leaf.
You'll need a clean plastic or ceramic flowerpot with drainage holes. If you're using a recycled flowerpot, help your youngster make a solution of 9 parts water and 1 part chlorine bleach. Soak the pot in it for a few minutes to kill fungi or bacteria that could infect the plant, and rinse thoroughly. Disinfect a sharp knife in the same manner. Pack the flowerpot with dry vermiculite, then place the pot in a saucer of lukewarm water for half an hour to thoroughly moisten.
Select a robust, healthy leaf from the middle row on the mother plant, and have your child break it off leaving most of the stem attached. If you're using a friend's or relative's plant, gently wrap the cutting in a damp paper towel until you can replant it. Lay the leaf on a work surface and, if your child is old enough, allow him to make a slanting cut through the petiole about 1 or 2 centimetres below the base of the leaf. Insert the leaf at an angle in the vermiculite with most of the leaf exposed. Use a toothpick to hold the leaf up a bit. Don't use rooting hormone because it may delay shoot development. Have your child cover the cutting with a glass jar or a tent of plastic film to keep humidity high, then place the cutting in a bright place away from direct sunlight - a north-facing window is ideal.
In two or three weeks, the leaf cutting will lift itself away from the toothpick, a signal that plantlets are beginning to form. Some varieties send up babies in a big hurry; others take a little longer. About 4 to 6 weeks after planting the cutting, you should have a healthy clump of as many as 8 plantlets, which your child can carefully divide and repot in 2 1/2-inch flowerpots, one per pot. Fill each pot with standard African violet planting mix, dig a hole for the plantlet's roots and place a teaspoon of damp vermiculite at the bottom. Avoid handling the fragile roots and replant the baby violets with the crowns just above the surface of the soil.