Bougainvillea is an ornamental woody vine native to South America. It's a topical vine, widely grown in the southern United States. It's a lively plant that will grow over fences and walls, and can sometimes choke out other plants that get in its way, so plant it where it will have free rein, and you'll be rewarded with a display of brightly colored blooms. Bougainvilleas can easily be propagated by stem cuttings, either softwood cuttings in spring or summer; or hardwood cuttings in fall and winter. The process is the same for both types of cuttings.
Cut a 4 to 5-inch piece of bougainvillea stem from a healthy plant with a sharp, clean knife. Take the cutting from a middle section of stem, not from a tip.
Fill a 4-inch pot with a mix of half sand and half potting soil. Mist the soil with a spray bottle until it's damp but not soggy.
Remove two-thirds of the bougainvillea's leaves nearest the cut end, leaving at least two upper leaves. Dip the cut end of the stem in rooting hormone, and plant the cutting with one-third of the stem in the soil. The leaves should be above, but not touching the soil. You can plant more than one bougainvillea cutting in the same pot, but don't allow the leaves to touch.
Put the pot in a plastic bag and seal the top of the bag. The environment in the bag must be kept humid, so open the bag and mist the soil when the soil appears dry.
Check the drainage hole in the bottom of the pot after about six weeks. If you see tiny, white roots, you'll know the cutting has taken root. Softwood cuttings taken in in spring or summer will take root in three months or less. Hardwood cuttings taken in fall or winter should take root in three or four months.
Move the bougainvillea outside after it takes root. If you live in a climate where the temperature drops below freezing, keep the bougainvillea inside until the weather warms up.