Lemon verbena (Aloysia citrodora) is a prized garden herb, celebrated for its intense lemon fragrance and diverse applications. Its distinct aroma, reminiscent of fresh lemons, makes it a versatile addition to both culinary endeavors and fragrant garden spaces.
Understanding Lemon Verbena
Lemon verbena (Aloysia citrodora) is a woody shrub, reaching 6 to 8 feet in height and width outdoors. Its slender, glossy green leaves release a powerful lemon scent when bruised.
Native to South America, lemon verbena thrives in warm, frost-free climates. It is a tender perennial, surviving year-round in USDA hardiness zones 8 through 11. In colder regions, it is grown as an annual or in containers moved indoors for protection.
Caring for Lemon Verbena
Lemon verbena flourishes in locations with ample sunlight, ideally six to eight hours of direct sun daily. Full sun encourages vigorous growth. In extremely hot climates, afternoon shade can prevent leaf scorch.
The plant thrives in rich, well-draining soil, preferring a slightly acidic to neutral pH (6.0 to 7.0). Good drainage is crucial, as lemon verbena is susceptible to root rot in waterlogged conditions. Incorporating organic matter like compost improves drainage and enriches nutrient content.
Consistent watering is beneficial, especially during the active growing season. Keep the soil consistently moist but not waterlogged, allowing the top 1 to 2 inches to dry before rewatering. Potted plants require more frequent watering than those in the ground.
Lemon verbena is a warm-weather plant, performing best between 70°F and 85°F (21-29°C). Temperatures below 40°F (4°C) can trigger leaf drop and dormancy. It is sensitive to frost, which can kill the plant.
Lemon verbena benefits from regular fertilization for lush growth. A balanced liquid fertilizer applied every four to six weeks during the growing season is sufficient. Alternatively, amending the soil with compost or manure tea provides a steady supply of nutrients.
Pruning maintains the plant’s shape and promotes bushier growth. Pinching back young plants encourages branching. A more substantial prune in late winter or early spring removes woody growth and stimulates new shoots. Regular harvesting also contributes to plant health.
Harvesting and Using Lemon Verbena
Harvest lemon verbena leaves throughout the growing season, with the best flavor often achieved when the plant is about to flower. Snip stems just above a leaf node to encourage new growth.
Remove up to one-quarter to one-half of the plant’s growth during each harvest to promote continuous production. Frequent harvesting keeps the plant from becoming leggy and encourages a bushier form. Fresh leaves offer the most intense flavor, but they can also be dried.
Lemon verbena is widely used in culinary applications, adding a bright, citrusy note without the tartness of lemon fruit. It is popular for herbal teas, infusing desserts like sorbets, custards, and cakes, and flavoring jams and syrups. The leaves enhance savory dishes, such as poultry, fish, and vegetable marinades. Beyond the kitchen, its fragrant leaves are used in potpourri and scented sachets.
Propagating and Common Issues
Propagate lemon verbena through stem cuttings, as seeds often have a low germination rate. Take 4 to 6-inch non-flowering softwood or semi-ripe cuttings from healthy stems in late spring or summer. Remove lower leaves and insert the cutting into a moist, well-draining rooting medium, such as soil and perlite. A humid environment, like a plastic bag covering the pot, aids rooting, which typically occurs within 3 to 4 weeks.
Lemon verbena is generally resistant to most pests and diseases outdoors. However, spider mites and whiteflies can be problematic, especially when plants are brought indoors or if conditions are dry. These pests feed on plant sap, causing yellowing leaves or a stunted appearance. Regularly misting plants deters spider mites, while insecticidal soap or neem oil manages infestations.
Leggy growth is a common issue, often from insufficient light or infrequent pruning. Ensure the plant receives adequate sunlight and regularly pinch back growing tips for a more compact, bushy form. Overwatering can lead to root rot, so proper drainage and careful watering are important.