When people speak of propagating, they usually mean taking cuttings — using pieces of stems, roots, and leaves to start new plants. (See image below.)

Taking a stem cutting.

Softwood stem cuttings, taken from spring until midsummer, root the quickest. During this time, plants are actively growing, and the stems are succulent and flexible. Here’s how to take a softwood stem cutting:

1. Use a sharp knife to cut a 4- to 5-inch-long (10 to 12 cm) stem (or side shoot) just below a leaf, and remove all but two or three leaves at the top.
2. Dip the cut end into rooting hormone.
   
   Rooting hormone is a powder or liquid containing growth hormones that stimulate root growth on cuttings. Some also contain a fungicide to control root rot. Local nurseries or garden centers carry the product.
3. Insert the cutting into a box or container (with drainage holes), filled with about 3 inches (8 cm) of moistened pure builder’s sand, vermiculite, or perlite.
4. Slip the container into a self-sealing plastic bag.
   
   Prop up the bag with something like toothpicks or short twigs so that the plastic doesn’t touch the leaves. Seal the bag to minimize water loss, but open it occasionally to let in fresh air.
5. Place the covered container in indirect light.
6. When the cuttings are well rooted (4 to 8 weeks, for most plants) and are putting on new growth, transplant them into individual containers of potting soil.
   
   As they continue to grow, gradually expose them to more light. When the plants are well established in the pots and continue to put on top growth, harden them off (acclimate them to your weather conditions) and plant them in their permanent garden location.
   
   To harden off new plants, gradually move them to more extreme temperatures and sunlight. Moving them from the porch to outside in partial sun and finally to full sun over a week’s time should do the trick.

Here are some easy-to-root plants to grow from stem cuttings:

• Perennials: Begonia, candytuft, chrysanthemum, carnations or pinks (Dianthus), geraniums (Pelargonium), penstemon, phlox, sage, sedum
• Woody plants: Bougainvillea, fuchsia, gardenia, heather, honeysuckle, ivy, pyracantha, star jasmine, willow

Divide And Plant-ER

Sometimes, the best source for plant material for propagating is neighbors and friends. If your neighbor has a plant you want to grow, just ask to take cuttings. (Gardeners love to share.)

Another great way to get new plants is through division, the process of pulling apart clumps of plants to create new clumps. (See image below.) As plants become established in a garden, most develop into larger and larger clumps made up of small plants. Dividing and then replanting these clumps is the easiest means of spreading and increasing them. Dividing works great with all but tap-rooted plants, namely plants with a main root that grows straight down, such as a carrot.

Use the following techniques to divide plants:

• Use a spade or digging fork to lift out a mature clump (usually 3 to 5 years old).
• Divide fine-rooted types, such as lamb’s ears, by hand, gently teasing apart the clump into separate plants.  ....read more