How to Grow Lemon Verbena Herb

Lemon verbena, also known by its Latin name, Aloysia triphylla, is a deciduous shrub that thrives outdoors in the warm temperatures of USDA hardiness zones 9 and 10. The plant is hardy to about 10 degrees Fahrenheit. In more temperate climates, gardeners grow the herb as a houseplant or in containers for easy transport indoors when temperatures drop. Outdoors or indoors, the lemon verbena herb requires only minimal care to produce the aromatic leaves beloved by gardeners and herbalists alike.

Starting Lemon Verbena Plants

Lemon verbena seeds are often difficult to find and the plant produces them only infrequently, but container-grown plants are typically available at well-stocked nurseries or through mail-order. Plants may also be started from cuttings, which should be taken during the summer months and rooted in moist soil in a shady location. For the best results, start from a container-grown specimen, as taking cuttings may cause the donor plant to wilt.

Planting Lemon Verbena

Plant lemon verbena outdoors in the garden in zones 9 and 10 only, as they cannot tolerate the temperatures in cooler regions. Choose a planting location that receives full sun and consists of fertile, humus-rich, well-drained soil for the best results. If the site has poor fertility, use a garden tiller to incorporate several inches of organic compost into the soil prior to planting. Space outdoor plants at least 12 inches apart to allow enough room for the shrub’s mature size.

In zones 8 and above, plant lemon verbena in a container filled with loamy potting soil. A mixture formulated for chrysanthemums or geraniums is ideal. Each potted plant requires a 10- to 12-inch container to promote optimal growth. Place the container indoors in an area that receives full sunlight throughout the day, such as a south-facing window. If a well-lit area is not available, place the plant under grow lights for four to six hours per day.

How to Grow Lemon Verbena Outdoors

After the initial planting, water lemon verbena herb thoroughly to initiate growth, and then refer to the following care tips for outdoor plants:

• Watering – Keep the soil moist, but not soggy, by watering about once per week. During periods of extreme heat or drought, more frequent applications may be necessary.
• Feeding – Lemon verbena plants are heavy feeders and require frequent fertilization throughout the growing season. For the best results, feed with fish emulsion once per month during the summer.
• Mulching – Apply a 2- to 3-inch layer of grass clippings or leaf mold in early summer to protect plants from the heat. Replenish in fall to protect against frost in the winter, if necessary.
• Pruning – Cut back lemon verbena plant in its third year of growth or it may become sparse and straggly. Prune in late fall or early winter, removing any excessively long, bare, damaged or diseased branches.

Growing Lemon Verbena in Containers

After potting, water the plant thoroughly to help the roots become established in their new home. Follow these tips for indoor/container care to keep the lemon verbena plant healthy and thriving:

• Watering – Keep the soil moist at all times, but do not allow standing water to accumulate around the plant’s roots. Water about once per week, or anytime the top of the soil feels dry to the touch.
• Feeding – Lemon verbena herb is also a heavy feeder when grown in containers. Apply fish emulsion according to the manufacturer’s instructions once or twice per month throughout the summer months.
• Pruning and Repotting – In the fall, cut back lemon verbena plants by about half their size and repot in fresh soil. Increase the size of the growing container only if you want the plant to grow larger. Pinch the plant’s tips throughout the growing season to promote bushy growth.
• Winter Care – Lemon verbena is deciduous and will lose its leaves in winter, even when grown indoors. When branches are bare, reduce watering to once every two weeks, keep the plant in bright, indirect light and do not fertilize. Return to the normal care routine when new growth resumes in spring.
• Special Care – Wash indoor lemon verbena leaves using a cloth dampened with lukewarm water about once per week to prevent pests from colonizing. Place the plant outdoors during warm, summer months, if desired, but make sure to place the container on bricks or rocks to prevent the roots from entering the ground from the bottom of the pot. Bring back indoors before temperatures drop in fall.

References:

Rodale’s Illustrated Encyclopedia of Herbs. Emmaus, Pa.: Rodale Books, 1998. Print.

John, and Rosemary Hemphill. What Herb is That?. First Edition ed. London: Pa: Stackpole Books, 1997, 1997. Print.

Smith, Miranda. Your Backyard Herb Garden: A Gardener’s Guide to Growing Over 50 Herbs Plus How to Use Them in Cooking, Crafts, Companion Planting and More. Emmaus, Pa.: Rodale Books, 1999. Print.

Creasy, Rosalind. Edible Herb Garden (Edible Garden Series). 1 ed. North Clarendon: Periplus Editions, 1999. Print.