Colorful hummingbird magnets, trumpet vines (Campsis radicans) bloom from spring to fall in orange, red or yellow. Propagate more of them from a friend's or neighbor's vine, or from your own, for more of these showy perennials. Take the cuttings in early summer and the new vines should be ready to plant in the garden by fall.
Trumpet vines or trumpet creeper plants can grow to 40 feet and are considered invasive in some areas. Trumpet vines can quickly overtake an area and these adaptable plants grow in U.S. Department of Agriculture plant hardiness zones 4 to 10. For fewer problems, choose smaller cultivars like 'Apricot' (Campsis radicans 'Apricot'), which grows in USDA zones 4 to 9, to only 12 to 15 feet tall. Prune the vines regularly to keep them in check.
Prepare Ahead of Time
Water the vine generously the day before taking the cuttings so there will be plenty of moisture in the stems and leaves. Take the cuttings in the morning before they lose moisture during the heat of the day.
Have your pot filled before you take the cutting. Use coarse builder's sand as the rooting medium and a choose a plant pot that is at least 3 to 4 inches deep. Choose a pot that has drain holes in the bottom. Rinse the sand thoroughly with clear water to remove dust and debris. Pour the wet sand into the container. The container must be large enough to allow for 5 inches of space for each cutting. Use several smaller containers or one larger one for multiple cuttings.
Make planting holes in the moist sand for the trumpet vine cuttings with a pencil. Each hole should be 1 inch deep, 2 1/2 inches away from the edge of the container and 5 inches apart.
Take and Process Cuttings
Stand the pruners, with the blades open, in a jar or large glass with enough household disinfectant in it to cover the blades and sterilize them. Let them soak for two to five minutes. Rinse the disinfectant off with clear water and dry them before using them. This helps prevent diseases on the cuttings, which can cause them to fail.
Cut 4- to 6-inch-long pieces of stem from the trumpet vine, making the cut just below a set of leaves. Each cutting should have three or four sets of leaves. Wrap the cuttings in moist paper towel and put the towel a plastic bag as soon as you take them. This helps prevent moisture loss.
Snip off the leaves on the lower one-half to two-thirds of each cutting and cut the remaining leaves back to a length of 2 inches. Remove any flowers and flower buds.
Pour rooting hormone into a small container or onto a piece of paper. Dip the bottom end of each cutting in rooting hormone and stick it in a planting hole. Firm the sand around the base of the cutting.
Mist the cuttings with a gentle mist from a spray bottle. The water should be room temperature. Slide the entire container into a clear plastic bag and seal it shut. Set the cuttings in a bright room where temperatures remain between 65 and 75 degrees Fahrenheit. Do not set them in direct sunlight.
Mist the cuttings each morning and water them if the sand begins to dry. Check for roots after a few weeks. To do this, tug gently on each cutting. You will feel resistance when they have formed roots.
Leave the plastic bag open and stop misting after the trumpet vine cuttings form roots to reduce the humidity level. Continue to keep the sand moist. Remove the plastic bag after a few days.
Plant the trumpet vine cuttings in individual containers one week after they develop roots. Use houseplant potting soil and make sure the container has drainage holes. Continue to keep them in bright, indirect light and water them when the top of the potting soil begins to dry.
Place the plants outside for a few hours each day in a shady spot that is protected from drying wind for two to three days. Start this hardening off process two months before the ground normally freezes in the fall. Allow the top 1 to 2 inches of potting soil to dry before watering.
Place the plants in direct morning sunlight for an hour, increasing the length of time by 30 minutes each day. After two weeks they should be used to four to six hours of direct sunlight and ready to be planted in the garden.