A shrub also known as incense bush due to its sweet fragrance, sweet almond verbena (Aloysia virgata) displays spiky clusters of tiny white flowers from early spring throughout summer. Sweet almond verbena, perennial in U.S. Department of Agriculture plant hardiness zones 9 to 11, reaches a height of 15 feet at maturity. Almond verbena roots easily from stem cuttings taken before the plant blooms in spring. You can also take cuttings in late summer and grow them indoors until the following spring.
Fill a celled planting tray with a rooting mixture of half peat moss and half sand or perlite. Water the mixture thoroughly, then set it aside to drain until the mixture is evenly moist, but not dripping.
Cut 3- to 5-inch stem tips from a healthy sweet almond verbena. Use a sharp knife or garden shears to cut the stems just above a leaf node.
Remove the leaves from the bottom one-half to two-thirds of the stem. Roll the bottom half-inch of the stems in powdered or liquid rooting hormone.
Make a planting hole in the center of each cell, using a small stick or similar object. Plant the stems in the holes with the leaves just above the rooting mix. Don't allow the leaves to overlap or touch the soil.
Cover the tray with clear plastic or slide it into a large plastic bag. Install sticks or drinking straws in the corners of the tray to prevent the plastic above the cuttings.
Place the tray in low light. Direct sunlight may scorch the cuttings.
Remove the plastic when the cuttings show new growth, which indicates the stems have successfully rooted, usually after about two weeks.
Transplant the new plants into individual 4-inch pots filled with regular commercial potting soil. Place the pots in a warm, sunny location and water as needed to keep the potting soil slightly moist. Don't over-water, as humid conditions may lead to rot and other diseases.
Allow the sweet almond verbena to mature for at least two to three more weeks before planting the new shrubs outdoors. If you live north of USDA zone 9, grow the plants indoors until all danger of frost has passed the following spring.